You are here: start » engineer-mechanical » machining

Table of Contents

Kennedy Kit - Style No 520b

  • Kennedy Kit Style 520b
  • Top Storage - Lid
    • Kennedy Top Storage Lid
    • Parts dish holder
    • magnetic clip
    • Angle Angle Gauge - Wixey
    • Digital clock
    • Flashlight
  • Top Storage
    • Kennedy Top Storage Lid
    • Screw driver
    • Eye loupe set
    • Micrometer, 0-1“
    • Scissors
    • Plyers
    • Pocket Protector
      • center punch, spring loaded - Harbor Freight #621
      • highlighter - yellow
      • machinist rule - SPI 6” long flexible steel rule
      • pen - medium (1.0mm) blue BIC cristal
      • pencil
      • pocket paper pad/notebook
      • sharpie - medium and fine (blue, red, black, green)
      • scribe with magnetic tip
    • Allen wrenches
    • Utility knife
    • tape measure
    • Opt-visor
    • Safety glasses
  • Drawer One Left
    • Kennedy Drawer One Left side
    • Machinist square
    • radius gauges
    • ear plugs
  • Drawer One Right
    • Kennedy Drawer One right side
    • Calculator
    • Pin Micrometer (possibly remove, limited use)
  • Drawer Two Left
    • Kennedy Drawer Two left side
    • Thread Micrometer
    • Knurler
  • Drawer Two Right Top
    • Kennedy Drawer Two right side - top
    • Screw Pitch Gauge
    • Thread Ring Gage
  • Drawer Two Right Bottom
    • Kennedy Drawer Two right side - bottom
    • surface roughness comparator
    • telescope bore gauge
  • Drawer Three
    • Kennedy Drawer Three
    • carbide inserts
    • center drill
    • dial indicator
    • magnifier
    • dial calipers
    • bore micrometer
  • Drawer Four
    • Kennedy Drawer Four
    • carbide insert
    • tool holders
    • CXA tool holders

Tool Box

Auto Mechanics Tool Box Setup

Lift Table

Machining Student Tool List

Safety Related - Organization - Cleaning - Tool Storage

References for Tool List

Tool Cart

Problem

  1. More tools than can fit in a tool box
  2. Not enough flat working surfaces in shop
  3. Can transport in back of truck with a) a dolly lift or b) another person. Yes you might be able to keep your tools at school/work but doubt they are insured.
  4. Would be great to have a dedicated workshop but always need to do work offsite say at jobsite, school, friend, family, and so on
  5. Want easy access to a few tools, instead of having to search through a drawer
  6. Tools to be self contained, don't get jumbled up when transporting

Solution

  1. \$100 Tech Cart from Harbor Freight with modifications
  2. Board along back so it can slide in the back of a truck, width of cart must fit between wheel wells on truck bed
  3. Extension on back
    1. tip onto back of tailgate
    2. taller then cart with lid open
    3. shelf with french cleat, to hang:
      1. tool holders
      2. mallet/dead blow hammer hook
      3. chip brush
      4. bin for micrometer, thread gage, etc
      5. hook for optivisor
      6. bench brush
      7. magnetic strip
        1. allen wrenches
        2. chuck key
        3. center drill
  4. Bottom shelf on side to hold Kennedy tool box, able to open top lid, bumper/curb on front of toolbox to keep secure but still able to access tools, have room behind toolbox to store optivisors in box
  5. Top shelf on side, opposite cart handle to provide working surface
  6. French cleat shelf on side to hold wrenches and long items that don't fit in drawers
  7. Can throw french cleat shelves in bag for transportation

Toolpost Holder Rack Examples

Garage Items

Lathe Tools

  • CXA 2XL (250-302XL) Oversize 1“ Quick Change Tool Post Holder
  • BXA 2XL (250-202-XL) Oversize 3/4” Quick Change Tool Post Holder
  • CXA 7 (250-307) Universal Parting Blade Holder Lathe Quick Change
  • Carbide Inserts (TCMT325* positive screw on) - Finishing
  • 3/4” Shank Tool Bit Holder - Threading
    • \$102.83 from Carbide Depot Kennametal item# 1281817 LSSR123D Threading Toolholder
    • 8 TPI ACME Thread - LT16ER8ACME in KC5025 grade order# 1743780
    • 10 TPI ACME Thread LT16ER10ACME
    • 12 TPI ACME Thread LT16ER12ACME
    • 16 TPI ACME Thread
    • \$238.50 from Carbide Depot Kennametal item# 1679780 LT16ERAG60CB KC5025 (can run at slower speeds 130 SFM)
      • recommended by Randy 5/3/2019, non-cresting style TPI 8-48 threads, also metric .5-3 mm Pitch, 3 cutting edges
    • \$125.00 from ebay discount_machine for Shars 12 Pc 3/4“ UN external indexable threading tool holder with inserts
  • 3/4” Shank Tool Bit Holder
    • \$50 ebay - All Industrial ALL-19925
      • A-L 0-degree
      • A-R 0-degree
      • B-L 15-degree
      • 3/4 BR-12 15-degree
      • E 30-degree for turning, facing, boring, chamfering, threading, and v-grooving
      • Turning Toolset Styles
      • Style A - straight shank, 0° side cutting edge angle (SCEA) - Machinery's Handbook, 27th Edition, p. 767
        • Figure 1-0 American National Standard Style A Carbide Tipped Tool, Machinery's Handbook, 27th Edition, p. 767
      • Style B - 15° side cutting edge angle (SCEA) - Machinery's Handbook, 27th Edition, p. 768
        • Figure 1-0 American National Standard Style B Carbide Tipped Tool, Machinery's Handbook, 27th Edition, p. 768
      • Style C and E - 15° side cutting edge angle (SCEA) - Machinery's Handbook, 27th Edition, p. 769-770
        • Figure 1-0 American National Standard Style C and E Carbide Tipped Tool, Machinery's Handbook, 27th Edition, p. 769-770
    • C6 Carbide Inserts with chipbreaker TCMT 32.52 - \$33 ebay - All Industrial ALL-20206
    • Kennametal Master Catalog - Turning Tools
  • Square Shape, Kennametal
    • SNMG432FW KCP10 order# 3749368 - has 8 cutting edges (4 corners and top & bottom)
      • SN = Square Negative
      • MG =
      • 4 =
      • 32 =
      • FW = Finish Wiper, the wiper feature does a second level cut to provide a smoother finish
      • KCP10 grade can cut without oil (KC730 needs oil)
      • \$16.66 from MSC Industrial Direct
    • Holder, Kennametal - MSRNR124B order# 1096149 - has a 15° lead angle (RT right hand)
      • \$89 from MSC Industrial Direct
      • LT left hand holder 1096159
      • 5/32“ allen wrench top clamp
      • 3/32” allen wrench locking pin

Jeff Jensen Toolholders and inserts

  • Intermountain Machining Supply, Inc - Greg Goetz, ggoetz@ims.supply, 208-321-9121 (office)
  • Kennametal Insert (turning and facing) - SNMG432FW KCP10 order# 3749368 (purchased 5/5/2019)
    • Chip Breaker FW (Finish Wiper) cuts steels depth of cut 0.008 to 0.080“ per side so diameter max 0.160”
    • MSC Part# 08332843 save 25% on orders of \$199 coupon code SAVE25H
  • Kennametal Insert holder - MSRNR124B order# 1096149
  • Kennametal Threading Insert item# 1679780 LT16ERAG60CB KC5025
  • Kennametal Threading Toolholder item# 1281817 LSSR123D

CSI Toolholders and Inserts

  • Insert Geometry for Cold Rolled/Mild Steel
    • Kennametal Insert Geometry and Grade for Cold Rolled Steel
  • Grade KCP10B produces excellent surface finishes on most steels and cast irons - problem have to high SFM and RPM
  • Grade KCP10 produces excellent surface finishes on most steels and cast irons - problem have to have high SFM and RPM
  • Grade KC5010 (KC730 and KC5010 use same carbide but KC730 can run 50 SFM slower which is needed on a manual lathe) works well on 1018 Cold Rolled Steel, only problem is the insert tip breaks easily - Jim at CSI.edu purchases these
    • KCU10 is a newer version of KC5010, so basically the same
  • Grade KC730 is best for low RPM, other inserts want to run at 1600 RPM min. Has a PVD thin gold coating.
    • TCMT3252LF KC730 order# 1162011 - Randy at Kennametal likes this best for manual machining
      • Carbide Depot - TCMT3252LF KC730 2LF = 2 is 1/32 = 0.030 min depth of cut, LF=Light Finish
      • 1/32 nose radius gives a better finish than the 1/64
      • TCMT3252LF KCP25B 5698121 (works at low RPM, works with hot-rolled)
      • TCGT3252LF KC5010 order# 1522949 - very good ground insert, gives good finish (good for Aluminum)
    • RPM = 3.82 SFM / Diam (revolutions per minute)
    • SFM = 0.262 X Diam X RPM (surface feet per minute)
    • Kennametal Cutting Speed for Cold Rolled Steel
  • Carbide Turning Insert
    • #1162011 TCMT32.52 LF Grade KC730 - can run at slower RPM like 400 TCMT3252LF KC730
    • TCMT325211 has nose radius 1/32, is it available in grade KC730 or KC5010? TCMT3252LF KC5010
  • Carbide Threading Inserts
    • #1112958 for aluminum and can be used with mild steel
    • #1112895 for mild steel
  • Kennametal Grade# NTP3R
    • Turning Toolset Styles
  • Kennametal Catalog#
    • NTP3R
    • NT3RK (recommended by Randy Kopka, Senior Analyst, Customer Application Support, na.techsupport@kennametal.com 1-800-835-3668, subject line - attention Randy)
  • Sandpaper with Cloth Backing to add a fine finish to 1018 steel

Select Carbide Insert Example

  • Step 1 - identify material cutting - P
  • Step 2 - select insert geometry - Kennametal SNMG
    • Kennametal Carbide Insert Geometry
    • Kennametal Insert Geometry - Negative Wiper
    • Minimum depth of cut .013“ at .005 in/rev
    • Minimum depth of cut .008” at .008 in/rev
    • Depth of cut range: .008“ to .080”
    • feed rate range: .005 to .020 in/rev
  • Step 3 - select insert grade - KCP10
    • 450 SFM for Steel (blue P0 to P6)
      • KCP30B
      • KCP30
      • KCP40B
      • KCP40

Cleaning Box

Safety

CNC Programming

CNC Programmers

  • Mark Terryberry LinkedIn mterryberry at haascnc dot com

CNC References

CSI MANT 140

  • Instructor: Jim Kellis 208-732-6379, jkellis@csi.edu
  • Department Chair, Trade & Industry: Kory Lloyd, 208-732-6811, klloyd@csi.edu

NIMS

Haas CNC Lathes at CSI

  • Model SL-10T serial# 3075860
  • Model SL-10 serial# 3085544

Haas VMC

ER Tool Holding System

  • ER Tool Holding System
  • ER Tool Holding System - Cross Section

ER Collet Chuck Tool Holders or ER Holder Class

ER Collet

  • Figure 1-0 ER Collet
  • ER 50
  • ER 40
  • ER 32
  • ER 25
  • ER 20
  • ER 16
  • ER 11
  • ER 8
  • Collet Dimensions
    • Figure 1-0 ER Collet Dimensions
  • Collet Types
    • Figure 1-0 ER Collet Types
    • Standard Collet
    • High-Performance Collet
    • Tap Collet
    • Sealed Collets

ER Collet Nut

  • Figure 1-0 ER Collet Nuts
  • Flush Nuts
  • Low-Friction Nuts
  • Coolant Nuts
  • Mini-Nuts

Tool

Turning - NIMS Content Area

  • NIMS Machining Level 1 Preparation Guide - Turning
  • Turning Speeds and Feeds
    • Cutting speed - is based on the distance the work moves past the tool based on the number of feet that passes the tool in one minute and is given in surface feet per minute.
      • cutting speed (fpm) feet per minute
  • Work Holding Devices and Basic Setup
  • Lathe Components
  • Turning Operations
  • Process Improvement and Troubleshooting
    • To improve a process, one must first understand the process. A competent machinist should be able to identify the root cause if a straight cut between centers measures as a taper. Measuring a taper (when a straight cut is intended) and moving the tailstock the proper amount based on the measurement is another skill needed to effectively and efficiently engage in turning operations. Other skill sets include the proper way to take the first cut on cast iron and hot roll steel, the root cause of lathe center runout, turning hard material and the effect of having the lathe tool above or below center.
  • Turning Safety
    • Safety knowledge and practice is an important component for lathe operations. The operator must know the basic personal protective equipment needed to effectively operate a lathe safely. Proper lifting techniques, learning how to find MSDS and HMIS information and some basic personal first aid are essential knowledge for all machinists. Other safety components involve the safe installation of chucks and collets as well as chip control and chip removal.
  • Lathe Controls
    • An understanding of basic lathe control mechanisms enables the machinist to utilize the lathe in an efficient and productive manner. Knowing how each control works and its function is imperative to any safe turning operation. Knowing how to use the feed reverse lever, half nut lever and the proper method to change speeds and feeds is imperative knowledge. Each manufacturer of lathes has unique methods of implementing lathe controls. It is the job of the machinist to become familiar with each particular set of lathe controls.
  • Single Point Threading
    • Single point threading is one of the fundamental skill sets needed to operate a lathe. The machinist must be familiar with thread angles, helix angles, thread pitch diameter, lead and different families of thread forms. Proper alignment of the threading tool as well as the proper location of the compound rest are essential setup steps needed to turn threads with a single point tool. A machinist must be able to calculate the proper infeed to prevent the thread from either being cut too deep or too shallow.
  • Tapping, Fits and Allowances
    • The turning process is often used to size shafts and holes for certain fits. Knowledge of the definitions of a fit and an allowance is essential prior to machining. The machinist should have a basic knowledge of the types of fits and be able to reference the Machinery's Handbook to determine the size of each component. Planning the sequence of operation is essential to prevent ruining a fit due to burrs and poor surface finish.
  • Process Control
    • Monitoring the process with process control techniques results in quality parts and customer satisfaction. The first step in any process control endeavor is knowing when the part is accepted or rejected. Basic knowledge of process control techniques such as inspection sheets, Pareto charts, capability studies and X bar/R charts are effective means of process control. The most common method of process control, besides the inspection sheet, is SPC (statistical process control) utilizing the X bar/R chart. The machinist must understand the definition of range, mean, upper control limit, lower control limit and sample size.
  • Tooling and Lathe Setup
    • Many lathe applications use tooling with carbide inserts. However, some lathe applications use high-speed steel tools that must be ground to the desired shape. The machinist should know the proper sequence for grinding the surfaces of the lathe tool applying the proper rake angles. Knowledge of the various methods of aligning the lathe centers and the degree if accuracy of each method depends on the tolerance of the work piece dimensions. Proper setups for facing and compound rest fundamentals are other essential skill sets included in this area.
  • Layout Procedures
    • Layout is the initial step in any machining process. Understanding the concepts and proper utilization of semi-precision and precision layout techniques is important for every machinist. The machinist should know the function of a scriber and the types of layout instruments used with surface plates.

Turning Speeds and Feeds and Depth of Cut

  • Reference
    • Technology of Machine Tools, 7th Ed by Krar, Gill, Smid
  • Material is 1“ round, material Aluminum
  • Step 1 - Lookup Cutting Speed (CS) feet/min of a material
    • “Lathe work cutting speed (CS) may be defined as the rate at which a point on the work circumference travels past the cutting tool.” (ibid, p. 370)
    • Aluminum
      • Rough Cut: 200 ft/min
      • Finish Cut: 300 ft/min
Lathe Cutting Speed (CS) feet per min (ft/min) for various materials
Material Turning and Boring - Rough Cut Turning and Boring - Finish Cut Threading
Aluminum 1060 Alloy 200 300 60
Delrin
Steel AISI 1020 90 100 35
  • Step 2 - calculate RPM or lathe spindle speed in revolutions per minute (r/min)
    • RPM = CS * 4 / D = 200 * 4 / 1 = 800 RPM which is too fast, take 1/3 of this = 266 RPM
      • CS = 200 ft/min for Aluminum
      • D = Diameter in inches
  • Step 3 - lathe feed controlled by the gearbox
    • distance the cutting tool advances along the length of the work for every revolution of the spindle
    • Aluminum
      • Rough Cut: 0.015 - 0.030 inches
      • Finish Cut: 0.005 - 0.010 inches
  • Step 4 - depth of cut
    • the tool feed is radius and the material removed is diameter
    • If I need to remove 0.010” of material, then depth of cut is 0.005“
    • Aluminum
      • Finish Cut: 0.005 -

Turning Speeds and Feeds

  • How do I determine the cut time (minutes)?
    • cut time = cut length / feed rate (IPM)
  • How do I determine the feed rate (IPM)?
    • feed rate = spindle speed (RPM) x cutting feed (IPR)
  • How do I determine the cutting feed (IPR, inches per revolution)?
    • the distance that the cutting tool or workpiece advances during one revolution of the spindle
  • ipm = feed rate (inches per minute)
  • ipr = cutting feed (inches per revolution)
  • rpm = spindle speed (revolutions per minute)
  • fpm = cutting speed (feet per minute)
    • sfm = cutting speed (surface feet per minute)
    • CS = cutting speed (older notation)
    • too low cutting speed (SFM or CS) produces discontinuous chips (BAD)
    • proper cutting speed (SFM or CS) produces continuous chips (GOOD)
    • too high cutting speed (SFM or CS) produces built up chips (VERY BAD)
    • Figure 1-0 Chip Types
  • Step 1 - lookup the surface feet per minute (SFM) for the material cutting on the lathe. What is your speed? respond with SFM not RPM
    • SFM - also called surface speed or simply speed is the speed difference (relative velocity) between the cutting tool and the surface of the workpiece it is operating on. It is expressed in units of distance along the workpiece surface per unit of time, typically surface feet per minute (sfm). (Destiny Tool - Understanding Speeds & Feeds)
    • Figure 1-0 Destiny Tool - Understanding Speeds & Feeds
  • Step 2 - find diameter of rotating part/tool. If drilling, use diameter of drill bit. If on the lathe, use diameter of workpiece. If on the mill, use diameter of cutter tool.
    • rough cut 0.001” any deeper will cause chatter
    • finishing cut 0.0002“ for accuracy and finish
    • see CNC Cookbook G-Wizard
  • Step 3 - calculate max RPM (THATLAZYMACHINIST recommends using 1/3 of max RPM)
    • actual max RPM = SFM x 3.82 / D
    • actual max RPM = SFM x 12 / (π x D)
      • 12 / π = 3.8197
    • estimated max RPM = SFM x 4 / D
  • Step 2 - calculate the feed rate (IPR, inches per revolution)
  • Definition of cutting speed
    • feet per minute (fpm)
    • surface feet per minute (sfm)
  • Definition of feed or feed rate, f the speed of the cutting tool's movement relative to the workpiece as the tool makes a cut
    • The feed rate is measured in inches per minute (IPM)
    • inches per revolution (ipr)
  • Calculating the RPM
    • spindle speed (rpm)
  • Identification of the RPM formula
  • Calculating the number of revolutions needed to move a lathe tool a given distance when given the feed per revolution
  • Time required to make one cut over a given length when given the RPM and feed per revolution
  • Calculating the RPM of a given drill diameter when drilling on a lathe
  • What about Material Removal Rate (MRR)? Seems like a balance, more material you remove the more wear and tear on equipment.

Turning - Step 1 - Select Workpiece Material Group

  • K - Cast Iron
  • Tool Steel
  • Stainless Steel
  • P - Steel
    • P0
      • ASTM A36 - hot rolled steel
      • AISI 1018 - cold rolled steel
    • P1
      • AISI 12L14 - cold rolled steel
  • Aluminum
  • Delrin
  • Kennametal Material Groups

Turning - Step 2 - Tool bit and insert geometry selection

  • Triangle Shape - TCMT32.52 LF Grade KC730
    • Kennametal# 1162011 Carbide Depot - TCMT3252LF KC730 at \$16 each
    • more economical, get 3 tips instead of 2, downside larger insert so difficult to get into tight spaces
  • Diamond Shape - DPGT3251HP KC5010
    • Kennametal# 1310719 Carbide Depot - DPGT3251HP KC5010 at \$14.50 each
      • Note HP is High Positive and typically used on Aluminum
    • use when need to get into tight areas on the lathe
  • Square Shape, Kennametal
    • SNMG432FW KCP10 order# 3749368 - has 8 cutting edges (4 corners and top & bottom) most economical 5/3/2019 from Randy - CSI purchased this
      • SN = Square Negative
      • FW = Finish Wiper, the wiper feature does a second level cut to provide a smoother finish
      • KCP10 grade can cut without oil (KC730 needs oil)
      • \$16.66 from MSC Industrial Direct
    • Holder, Kennametal - MSRNR124B order# 1096149 - has a 15° lead angle
    • If experience chatter, try the following
      • increase or decrease RPM
      • tighten workpiece tailstock
  • Kennametal Catalog Numbers - Interactive Catalog
    • CNMG432FP (0.030 max depth of cut) KCP10 and KCP25B
      • Holder 80 deg end (MCLNR124B for turning and facing
      • Holder 100 deg end MCKNR124B (facing)
    • CNMG432FP
      • C - Insert Shape, Rhomboid
      • N
      • M
      • G
      • 4
      • 3
      • 2 - Corner Radius
      • FP
    • Figure 1-0 Kennametal Catalog Numbers
  • Corner Radius, RE
    • typically 1/64” or 1/32“
      • 1 = 1/64”
      • 2 = 2/64“ or 1/32”
      • 3 = 3/64“
      • 4 = 4/64” or 1/16“

Turning - Step 3 - Insert Grade

  • Manual Lathe - machining cold rolled steel
  • KC730 is best grade for this, even with 1600 RPM and 0.0012 in/rev (#1 IATX gear setting on Sharp lathe) feed the finish is smooth but looks blemished
    • Figure 1-0 KC730 Finish
    • Figure 1-0 KC730 Finish - Close up
  • KCU10 is a newer version of KC5010 (owned by csi.edu), both are a good choice
  • Figure 1-0 Insert Grade - KCU10

Turning - Step 4 - Feed Rate and Depth of Cut

  • Lookup manufacture recommended feed rate and depth of cut
    • Figure 1-0 Depth of Cut

Turning - Step 5 - Cutting Speed (SFM or FPM)

  • Lookup cutting speed of insert grade
    • KC730 has 400 SFM (Surface Feet per Minute or FPM=Feet Per Minute)
    • KCU10 and KC5010 has 450 SFM
    • Figure 1-0 Cutting Speed Chart - Kennametal
  • Machinery's Handbook, 27th Edition, p. 1016
  • Figure 1-0 Cutting Speed Formulas, Machinery's Handbook, 27th p. 1016

Turning - Step 6 - Spindle Speed (RPM)

  • Lookup Spindle Speed (RPM = Revolutions Per Minute)
  • Machinery's Handbook, 27th Edition, p. 1016
  • Figure 1-0 RPM for Various Speeds, Machinery's Handbook, 28th p. 988

How to make these parts

  • How would I make a flange? Allied Group Flanges has several flanges that can be purchased. When I made a flange, the hole pattern only fit in one setting, that is if I rotate the flange, then the holes didn't line up. This is due to the difficulty of laying out the pattern and the drill bit on the drill press wandering a little bit.

Circular Hole Layout

  • “A very practical use for this kind of calculation is in spacing bolt holes or otherwise dividing a circle into any number of equal parts. It is easy enough to get the length of each arc of the circumference by dividing 360° by the number of divisions, but what we want is to find the chord or the distance from one point to the next in a straight line as a pair of dividers would step it off. First divide 360° by the number of divisions - say 9 - and get 40° in each part. Fig. 5 shows this and we want the distance shown or the chord of the angle. This equals twice the sine of half the angle. Half the angle is 20° and the sine for this is 0.342. Twice this or 0.684 is the chord of the 40° angle for every inch of radius. If the circle is 14 inches in diameter the distance between the holes will be 7 times 0.684 or 4.788 inches. This is very quick and the most accurate method known.” (American Machinists' Handbook, 2nd Edition, by Fred H. Colvin and Frank A. Stanley, p. 523)
    • Figure 1-0 American Machinists Handbook, 2nd Edition by Fred H. Colvin and Frank A. Stanley, p. 523

Metal Characteristics

Ferrous (containing Iron, Fe)

Cast Iron

  • Malleable Iron - can be hammered into shape without fracturing
  • Use carbide cutting tools when working with Iron, Fe
  • Don't use cutting fluids on cast iron, use compressed air if a coolant is needed

Machining Iron and Hot-Rolled Steel

  • “The surface of ferrous metal castings has a scale that is more difficult to machine than the metal below/within. Some scale is more difficult to machine than others, depending on the foundry sand used, the casting process, the method of cleaning the casting, and the type of metal cast. Special electrochemical treatments sometimes can be used that almost entirely eliminate the effect of the scale on machining, although castings so treated are not frequently encountered. Usually, when casting scale is encountered, the cutting speed is reduced approximately 5 or 10%. Difficult-to-machine surface scale can also be encountered when machining hot-rolled or forged steel bars.” (Machinery's Handbook, 28th Edition p. 979 of 3455)

Nonferrous (without Iron)

Measurements

Micrometer

  • 0-1 inch on the sleeve
  • 1 = .100” or one-hundredth thousandths
  • vertical tick marks = 0.025“ or 25 thousandths
  • right horizontal tick marks = .001” or 1 thousandths
  • left horizontal tick marks = .0001“ or one tenth of one thousandths (machinists don't call it 1 ten-thousandths like everyone does)
  • Harbor Freight Digital Micrometer
  • How to read an inch micrometer by ET Prof - excellent discussion on micrometer

Finding Center

  • “Centering Parts to be Turned.—As previously mentioned, there are a number of different methods of forming center-holes in the ends of parts that have to be turned while held between lathe centers. A method of centering light work, and one that requires few special tools, is first to locate a central point on the end and then drill and ream the center-hole by using the lathe itself. Hermaphrodite dividers are useful for finding the center, as illustrated at A, Fig. 25, but if the work is fairly round, a center-square B is preferable. A line is scribed across the end and then another line at right angles to the first by changing the position of the square; the intersection of these two lines will be the center, which should be marked by striking29 a pointed punch C with a hammer. If a cup or bell center-punch D is available, it will not be necessary to first make center lines, as the conical part shown locates the punch in a central position. This style of punch should only be used on work which is fairly round.” (Turning and Boring by Franklin D. Jones, p. 29)
  • Centering Work for the Lathe by C.W. Woodson, Popular Science, Oct 1943, p. 486

Using a center drill

  • Figure 1. Table 6. American National Standard Combined Drills and Countersinks - Plain and Bell Types, Machinery's Handbook, 27th Edition by Industrial Press, p. 873
  • Figure 1-0 Centering Work for the Lathe by C.W. Woodson, Popular Science, Oct 1943, p. 486

Measure Diameter

  • Toms Techniques - Common Methods of Measuring the Diameter of a Hole
  1. Drill Bits
  2. Inside Calipers - transfer to micrometer to measure
  3. Hole Gage Amazon - Triton 4 piece small ball bore
  4. Telescoping Gauge Set from Harbor Freight - transfer to micrometer to measure
  5. Pin Gage Set

Threading

  • Identify bolt size, screw thread form, external or internal threads, TPI and class. For example:
    • 1/2” bolt diameter
    • screw thread form and series: Unified National Course (UNC) threads
    • External threads
    • 13 Threads Per Inch (TPI)
    • Class of Fit
      • Class 1A (external) and 1B (internal)
        • Loose fit between mating threads, ideal for quick assembly and disassembly, where speed is more important than precision. This class is seldom used.
      • Class 2A and 2B
        • ideal for general assembly fasteners and is the most common class of fit found on general-purpose nuts and bolts. Easy to assemble and still offer enough thread engagement to achieve considerable strength.
      • Class 3A and 3B
        • has little or no clearance between mating threads, used when a very accurate or high-strength assembly is required. This class of fit is more expensive to achieve since its production must be monitored closely in order to ensure accuracy. (Precision Machining Technology, p. 417)
  • Figure 1-0 Unified Screw Threads in Machinery's Handbook, 27th Edition, p. 1740
  • Step 0 - prepare workpiece by facing and turning and countersink ends with a center drill
    • Figure 1-0 Countersink Center Drill in Machinery's Handbook, 27th Edition, p. 873
  • Step 1 - determine finish diameter of the work piece/bolt, threads per inch, and
  • Step 2 - determine threads per inch (TPI)
  • Step 3 - determine feeds and speeds
    • Spindle speed, N in revolutions per minute (rpm) = 12V/πD, where V = cutting speed in feet per minute, D = diameter of workpiece (Machinery's Handbook 27th, p. 1016)
      • recommend max 100 RPM, too slow tears the metal, too fast and difficult to disengage thread cutting within the thread relief so you can easily damage the workpiece or tool.
    • “The feed used for tapping and threading must be equal to the lead (feed = lead = pitch) of the thread being cut” (Machinist Handbook, 27th, p. 1064)
  • Step 3 - Machinery Handbook
    • Major diameter (used turn workpiece to this diameter range)
    • Minor diameter (used to determine depth of cut for the thread and thread relief groove or undercut)
      • Minor Diameter Tolerance (External Threads) (1) UNR Classes. To intersection of rounded root with its centerline (see Figs. 2 and 3), equals pitch diameter tolerance for class of thread specified, plus 0.10825318P (see Table 5). (2) UN Classes 1A, 2A, and 3A. To intersection of flat root with flanks of threads (see Figs. 2 and 3), equals pitch diameter tolerance for class of thread specified, plus 0.21650635P (see table 5). (ASME B1.1-2003 UNIFIED INCH SCREW THREADS, p. 58)
      • Table 4 Increments in Pitch Diameter Tolerance - Class 2A
    • Depth of cut is Major - Minor diameter (don't be confused with radius or diameter, lathe manufactures understand you can't cut a radius on the lathe, only can cut diameter so the dial dimensions are for diameters)
    • Compound Rest/Slide measures true distance which is the radius
    • Carriage Cross Slide and associated DRO measures diameter, because you can't cut radius on a lathe, half the distance of the Compound rest. So moving the cross slide 0.010 actually moves .005 and cuts the material .005 on each side.
    • Fig 1 - Cutting Screw Threads
  • Step 4 - face workpiece and if going to use the tail stock to hold the workpiece, add center drill
  • Step 5 - turn workpiece to within major diameter (nominal diameter - allowance) range
  • Step 6 - cut thread relief groove/undercut to the thread minor diameter using parting blade
  • Step 7 - cut chamfer to depth of minor diameter at beginning of thread
  • Step 8 - lathe - change gears to required TPI and reduce spindle RPM speed to 1/4 turning speed around 70 RPM for mild steel.
  • Step 9 - rotate compound rest in-feed to 29-29.5 degrees. Both cross slide and compound set to 0. Use center/fishtail gage to verify 60 degree angle of cutting tool and proper alignment with workpiece.
  • Step 10 - paint layout fluid (Dykem) on workpiece, touch off work piece and do a very light pass (0.001“). Use thread gage to measure markings.
    • engage half-nut lever at the same number to avoid problems
    • “Usually, even-number threads per inch can be cut by engaging the half-nut lever at any number on the thread dial, and odd-number threads per inch are cut by engaging the half-nut lever at the odd numbers on the dial.” (Precision Machining Technology, p. 425)
    • MSC Direct screw pitch gage
  • Step 11 - cross slide depth of cut = .75 H
    • H = cos30 / TPI = .86602540 / TPI
    • compound rest depth of cut = .75 Pitch (remember Pitch = 1/ TPI)
      • depth of cut = compound-rest distance x cos 30 degrees, 0.010” cos 30 = 0.00866“
    • Benefits of using compound rest
      • cut only on one side of the bit
      • faster - only have to advance the compound-rest/slide, don't have to worry about DRO, just turn cross slide out one full turn, move carriage back to start of the thread, advance cross fee back in one full turn, then advance compound rest/slide (e.g. 0.002”) to make another pass on the threads
    • Disadvantage - have to calculate the thread depth using cos 30 degrees
    • Figure 1-0 Thread Definition, Precision Machining Technology, p. 416
    • Formula to calculate the depth of v-thread, d see Machinery's Handbook 27th Edition, p. 1725
      • Figure 1-0 Machinery's Handbook 27th, p. 416
  • Step 12 - measure pitch diameter
  • Step 13 - screw on nut
    • Not accurate, can have the nut fit but the no-go gage doesn't fit, thread cut to deep
  • Figure 1-0 Thread Definition, Precision Machining Technology, p. 416
  • Figure 1-0 Thread Definition, Kennametal.com, p. D-82
  • Popular Science Oct 1941, Figure 1-0 Popular Science, Oct 1941, p. 193
  • Figure 1-0 Lathe - Cross and Compound Slides

Thread Standard

  • C:\Users\Public\Documents\Autodesk\Inventor 2020\Design Data\XLS\en-US\thread.xls
    • worksheet tab: ANSI Unified Screw Threads

Thread Micrometer

  • NIMS Questions
    • [Q] A thread micrometer is used to measure what dimension on an external thread?
      • A. Major diameter
      • B. Minor diameters
      • C. Thread helix angle
      • D. Pitch diameter
    • [A] Pitch diameter
      • Major diameter can be measure with a normal micrometer
      • Minor diameter can NOT be measured but the depth of cut on the compound rest measures true radius, so could calculate the minor diameter
      • Thread helix angle is also known as the lead angle which is 30°
        • Helix Angle
          • see Machinery's Handbook, 27th Ed, p. 1966

Threading Videos

  • Overview of Thread Making - not helpful if wanting to learn how to cut threads on a manual lathe

Drilling

  • Figure 1-0 Typical types of machining operations depicted on working drawings, Fundamentals of Modern Drafting by Paul Ross Wallach, Chapter 18 - Working Drawings, p. 323

Drill Presses

  • Home Depot
    • WEN 5 amp 12“ variable speed benchtop drill press - \$300
  • Harbor Freight
    • Central Machinery 13.5 amp 20” 12 speed production drill press - \$700
    • Central Machinery variable speed benchtop mill/drill machine - \$800 with R8 spindle taper
    • Central Machinery 9 speed vertical milling machine - \$2500 with R8 spindle taper

Drill Press Vise

Jaw Pads

Drill Press Repairs - Quill Spring

Spot vs Center Drill

Tap and Die

  • Tap Size Chart from CustomPartNet.com gives the tap size, tap drill size, threads per inch (TPI)
  • Drill bit, Tap and Die Set
    • Irwin Tools. Tubalcain recommends HSS (High Speed Steel) taps instead of carbon steel (cheaper). Cannot sharpen taps so trash if dull.
  • Tap Blocks
  • How to layout, drill and tap a hole using a drill press by www.lewisrazors.com
    • Ways to tap a hole straight - Part A by Lyle Peterson (a.k.a tubal cain or MrPete222, recommends using a counter bore about half way through the material with a larger drill bit, for example he used a tapper tape (7-8 tapper teeth) instead of a plug tap (3-4 tapper teeth), use cutting oil, turn about one full turn of the tap, then back it off, 5/16-18 threads per inch, then use a 1/4” drill bit for the entire hole, then counter bore with 5/16“ about halfway down. This helps the tap to start straight. Also shows how to use a Tap Handle Level from Edge Technology Products.com. Also shows the hand tapper guide. Lastly, using a homemade circular guide block
  • Tapping Perpendicular Holes - Part B - On the Drill Press by Lyle Peterson (a.k.a. tubalcain or MrPete222)

Spray Adhesive and Double sided Tape

Band Saw

  • Figure 1-0 Harbor Freight Band Saw Item# 93762
  • Harbor Freight 4x6 Horizontal Band Saw Specifications
  • Cutting ASTM A36 Mild/Low Carbon Steel
    • Cutting 1 inch solid round of ASTM A36 steel with 10/14 blade and 200 fpm, took 2 min 30 sec to complete.
    • Speed 200 fpm (feet per minute), cut/feed rate = 1.27 in2/min
      • From Machinery's Handbook, Material Steel (A36 Shapes) use 270 fpm
  • 64-1/2 in. x 1/2 in. Supercut Bandsaw Blade bimetal bandsaw blade 10-14 teeth per inch, cost \$28 for one blade
  • Figure 1-0 Band Saw Blades from Machinery's Handbook 27th Edition, p. 1141-2
  • Figure 1-0 Band Saw Blade Tooth Selection by Ellis Manufacturing Company, Inc
  • “The size and character of the chips being produced are the best indicators of the correct feed force. Chips that are curly, silvery, and warm indicate the best feed rate, the band speed, or both. If the chips are thin or powdery, the feed rate is too low, so increase the feed rate or reduce the band speed.” (Machinery's Handbook 27th Edition, p. 1140)
  • Super Cut
  • Figure 1-0 www.supercutbandsaw.com
  • Figure 1-0 Band Saw Blade Selection, Machinery's Handbook 27th Edition, p. 1138
    • “The tooth selection chart above is a guide to help determine the best blade pitch for a particular job. The tooth specifications in the chart are standard variable-pitch blade sizes as specified by the Hack and Band Saw Association. The variable-pitch blades listed are designated by two numbers that refer to the approximate maximum and minimum tooth pitch. A /6 blade, for example, has a maximum tooth spacing of approximately 1/4 inch and a minimum tooth spacing of about 1/6 inch…. To use the chart, locate the length of cut in inches on the outside circle of the table (for millimeters use the inside circle) and then find the tooth specification that aligns with the length, on the ring corresponding to the material shape. The length of cut is the distance that any tooth of the blade is in contact with the work as it passes once through the cut. For cutting solid round stock, use the diameter as the length of cut and select a blade from the ring with the solid circle. When cutting angles, channels, I-beams, tubular pieces, pipe, and hollow or irregular shapes, the length of cut is found by dividing the cross-sectional area of the cut by the distance the blade needs to travel to finish the cut. Locate the length of cut on the outer ring (inner ring for mm) and select a blade from the ring marked with the angle, I-beam, and pipe sections.” (Machinery's Handbook 27th Edition, p. 1138)
    • “Example: A 4-inch pipe with a 3-inch inside diameter is to be cut. Select a variable pitch blade for cutting this material.\\The area of the pipe is p/4 x (42 - 32) = 5.5 in.2 The blade has to travel 4 inches to cut through the pipe, so the average length of cut is 5.5/4 = 1.4 inches. On the tooth selection wheel, estimate the location of 1.4 inches on the outer ring, and read the tooth specification from the ring marked with the pipe, angle, and I-beam symbols. The chart indicates that a 4/6 variable pitch blade is the preferred blade for this cut.” (Machinery's Handbook 27th Edition, p. 1138-9)

Harbor Freight Bandsaw Modifications

Bench Grinder

  • 8-inch grinding wheel - better approach angle than 6“
  • Variable Speed (2000-3400 RPM)
  • Light
  • 5 amp 0.9 hp
  • arbor size 5/8 in
  • \$135 Hercules 8-in variable speed bench grinder with light Harbor Freight
  • \$190 Delta 8-in variable speed bench grinder with light Lowes
  • \$140 Dewalt 8-in bench grinder Dewalt 8-in bench grinder from Lowes
  • \$153 Wen 8-in variable speed bench grinder
    • recommends Hercules 8 inch variable speed bench grinder

Bench Grinder Pedestal

Pedestal Modifications

  • Lead Feet
    • Melting Safety
      • Wear eye protection
      • Have fan to blow fumes away, do it outside
      • Face mask
      • Doing boil the lead
    • Cast Iron Melting Pot - caution avoid molten metal and water, will cause an explosion
      • Lodge Melting Pot LMP3 - \$18
      • Ace Hardward - Lodge LMP3 - \$15
      • Flux - to draw out the impurities and create the slag, try using borax acid or parrafix wax (candle) or saw dust - carbon. What about cardboard?
      • pour into cast iron or stainless steel pan to make ingots
    • Valve Packing with Oakum

Bench Grinding Wheel

  • Amazon 8" Green Silicon Carbide Grinding Wheel \$38 each
  • Norton Abrasives
  • Bauer 8" Bench Grinding Wheel \$10
  • Grinding Wheel Explained
  • Abrasive Type
    • A = regular aluminum oxide
    • WA = white aluminum oxide
    • SD = synthetic diamond
    • ASD = synthetic diamond, metal coating
    • FA = semi-friable aluminum oxide
    • PA = pink aluminum oxide
    • SA (HA) = single crystal aluminum oxide
    • AZ = zirconium oxide
    • C = black silicon carbide
    • GC = green silicon carbide - for high speed steel (HSS)
  • Grain Size
    • Course
      • 10
      • 12
      • 14
      • 16
      • 20
    • Medium
      • 30
      • 36
      • 46
      • 54
      • 60
    • Fine
      • 70
      • 80
      • 90
      • 100
      • 120
    • Very Fine
      • 220
      • 240
      • 280
      • 320
      • 400
  • Grade (strength of bond) - friability
    • Soft (A-H) use for harder materials like steel
    • Medium (I-S)
    • Hard (T-Z) use for small items
  • Structure (space between grains)
    • Dense to Open (1-15)
    • Dense - use on hard material
    • Open - use on
  • Bond Type
    • V - vitrified
    • B - resinoid
    • R - rubber (use for polishing)
    • O - MgO
    • E - epoxy
    • M - metal
    • EP - electroplated

Metal Files

Milling

  • “In Fig. 109, E represents a view of the face of a milling cutter, and F a sectional view of the same, while G represents a piece of work passing under the cutter and not between the cutters, as shown in the case of the work D. The arrow H denotes the direction in which the cutter E would require to revolve, and the arrow I the direction in which, in that case, the work would require to travel; from which it will be perceived that the lateral strain placed upon the work by the cut is in a direction to force the work back from the cutter, and this must always, in the use of milling-tools, be the case, and is a very important consideration for the following reasons: From the breadth of cut taken by a milling-tool, and from the acute angle at which the teeth of the cutter strike the cut when the work passes below the circumference of the cutter, the strain due to the cut is immense; and were this strain in a direction to drag or draw the work below or towards the cutter, the latter would, from the spring of the spindle, rip into the work and tear its own teeth off.” (Complete Practical Machinist, The: Embracing Lathe Work by Joshua Rose,p. 304)
  • Figure 1-0 Milling - Climbing vs Conventional, CNC Machining for Engineers and Makers, p. 21
    • Figure 1-0 Complete Practical Machinist, The: Embracing Lathe Work by Joshua Rose, p. 302
  • “Thus, in Fig. 111, suppose A to be a milling-cutter revolving in the direction of the arrow B, and C to be a piece of work travelling in the direction of D, it will be readily perceived that there will be an enormous strain in a direction to force the work from its chuck or clamps and drag it under the cutter.” (Complete Practical Machinist, The: Embracing Lathe Work by Joshua Rose, p. 304)
    • Figure 1-0 Complete Practical Machinist, The: Embracing Lathe Work by Joshua Rose, Fig. 111, p. 304
  • Figure 1-0 Milling Cutters from Metal Cutting 4th by Trent, p. 15
  • Vintage Machinery Keith Rucker - Machine Shop Basics: Setting up a Vise on a Milling Machine

Sine Plate

Vice Jaw Plates

Lathe

  • Quick Change Tool Post

Lathe Tool Troublshooting Check List

  • Figure 1-0 Lathe Tool Troubleshooting Check List, Machinery's Handbook, 27th, p. 1014
    • Machinery's Handbook, 27th Edition, p. 1015-6

Crankshaft

Sherline Lathe

Lathe Purpose

  • The lathe only produces three types of cuts, which cuts can then be used for drilling, cutting tapers, threading, grinding, plunge cuts (parting)
  1. Turning - cutting tool is moved parallel to the lathe axis, removes material from the outside diameter of the work piece
  2. Facing - cutting tool is moved perpendicular to the lathe axis, removes material from the end or edge of the part
  3. Boring - cutting tool removes material from the inside diameter of the work piece
  • Figure 1-0 Tool Bit Shapes - US Army TC 9-524, p. 7-7
  • Figure 1-0 Nine Most Popular Shapes of Lathe Tool Cutter Bits

Select Cutting Conditions

  1. select depth of cut
  2. select feed rate (inches per revolution, ipr)
  3. select cutting speed (feet per minute, fpm or surface feet per minute, sfm)
  4. calculate spindle speed (revolutions per minute, rpm)
  • Figure 1-0 Lathe turning showing a vertical cross-section at top right and a detail of the insert geometry at bottom right. Metal Cutting 4th by Trent, p. 10

Turning

  • National Maritime Research Institute - Chapter 3. How to Use a Lathe
  • Set of Lathe Turning Tools from Turning and Boring by Franklin D. Jones, p. 54
  • Custompartnet.com - Turning
  • Turning Speed and Feed Calculator
  • Turning Speed and Feed Calculator
  • Turning tool bits - AR, AL, BR, BL, TE where R is right and L is left. Letter A and B designate the angles of the cutting edge. Mini Lathe Users Guide
  • TAR = T indicates that it holds triangular inserts, A indicates the insert has a zero degree side angle, R indicates right hand tool (i.e. right hand tools cut from right to left). See LittleMachineShop.com Chris Tips
  • TAL = T indicates that it holds triangular inserts,
  • TBR = T indicates that it holds triangular inserts, B indicates the insert has a 15° side angle, R indicates right hand tool
  • TBL = T indicates that it holds triangular inserts, B indicates the insert has a 15° side angle, L indicates left hand tool (cut from left to right)
  • TE = T indicates that it holds triangular inserts, E indicates the insert has a 30° side angle. In other words, the point is centered.
Radius/Direct Reading vs Diameter/Actual Reading

Facing

Parting/Cut-Off or Plunge Cuts

  • “Parting is the process of cutting off a piece of stock while it is being held in the lathe. This process uses a specially shaped tool bit with a cutting edge similar to that of a square-nosed tool bit. When parting, be sure to use plenty of coolant, such as sulfurized cutting oil (machine cast iron dry). Parting tools normally have a 5° side rake and no back rack angles. The blades are sharpened by grinding the ends only. Parting is used to cut off stock, such as tubing, that is impractical to saw off with a power hacksaw. Parting is also used to cut off work after other machining operations have been completed (Figure 7-59). Parting tools can be of the forged type, inserted blade type, or ground from a standard tool blank. In order for the tool to have maximum strength, the length of the cutting portion of the blade should extend only enough to be slightly longer than half of the workpiece diameter (able to reach the center of the work). <b>Never attempt to part while the work is mounted between centers</b>. Work that is to be parted should be held rigidly in a chuck or collet, with the area to be parted as close to the holding device as possible. Always make the parting cut at a right angle to the centerline of the work. Feed the tool bit into the revolving work with the cross slide until the tool completely severs the work. Speeds for parting should be about half that used for straight turning. Feeds should be light but continuous. If chatter occurs, decrease the feed and speed, and check for loose lathe parts or a loose setup. The parting tool should be positioned at center height unless cutting a piece that is over 1-inch thick. Thick pieces should have the cutting tool just slightly above center to account for the stronger torque involved in parting. The length of the portion to be cut off can be measured by using the micrometer carriage stop or by using layout lines scribed on the workpiece. Always have the carriage locked down to the bed to reduce vibration and chatter. <b>Never try to catch the cutoff part in the hand; it will be hot and could burn.</b>” (Fundamentals of Machine Tools, US Army TC 9-524, p. 7-33)
    • Figure 1-0 Parting from Fundamentals of Machine Tools US Army TC 9-524, Figure 7-59, p. 7-33
  • Tips
    • Make sure the parting tool is square/perpendicular to the part, if not, will bind and break the part or tool.
    • Tubal Cain's Machine Shop Tips 35 - Part 1: Parting on the Lathe

Figure 1-0 Tubal Cain's Machine Shop Tips 35 - Part 1: Parting on the Lathe - Compound Angle

  • Tubal Cain's Machine Shop Tips 36 - Part 2: Parting on the Lathe
  • Tubal Cain's Machine Shop Tips 37 - Part 3: Parting on the Lathe - using ISCAR cut off tool
  • Tubal Cain's Machine Shop Tips 37 - Part 4: Parting on the Lathe - brass plumb bob and Popular Mechanics Nov 1944
  • Tom's Techniques - Common Sense Machining - Parting on the Lathe

Slotting

Boring

Cylinder Hone

Knurling

  • Speeds and Feeds for Cut Knurling
  • Turning Formula Calculator to convert speed in feet/min to rev/min
  • Eagle Rock Technologies Inc - Knurls
  • Figure 1-0 Knurling Tips - Popular Science, July 1941, p. 179
  • Figure 2-0 Knurl example in plans - Fundamentals of Modern Drafting by Paul Ross Wallach, p. 326
  • Sherline Knurling Tool Holder
  • How to Run a Lathe, for the Beginner on Google Books
  • Figure 1-0 How to Run a Lathe, for the Beginner by South Bend Lathe, p. 26
  • “Knurling is not strictly a machining operation as no metal is cut. It is rather a forming operation in that hard patterned knurls are pressed into work, depressing and raising the surface of the metal into the knurl pattern. As with all other forming operations, the work can be no better than the pattern-your knurling no better than your knurls. Be sure that knurls are sharp and clean-cut (preferably hob-cut) and properly hardened. Since to make a true uniform knurling the pressure on both knurls must be uniform, select a knurling tool that is self-centering, that automatically equalizes the pressure on the knurls and has sufficient strength to withstand the terrific end and side thrusts encountered in this operation.” (The Care and Operation of a Lathe by Sheldon Machine Co., Inc., p. 80-81)
  • “Before starting to knurl, remove the work from the lathe and scribe lines indicating the part to knurled. In knurling, the back gears must be used and the lathe operated at slowest back-geared speed for best results. Always engage the back gears while the lathe is idle (never when it is running as this can strip the gears). (The Care and Operation of a Lathe by Sheldon Machine Co., Inc., p. 80-81)
  • “Knurling exerts extreme thrust against centers and bearings. This thrust can be materially lessened if the knurling tool is fed to the work at a slight angle off from perpendicular to the line of the work, so that the right side of the knurl engages the work first.” (The Care and Operation of a Lathe by Sheldon Machine Co., Inc., p. 80-81)
  • Figure 1-0 The Care and Operation of a Lathe by Sheldon Machine Co., Inc., p. 80-1
  • Figure 1-0 Dorain Tool - Knurl Patterns, p. H-12

Knurling - Turing and Boring by Jones

  • Figure 1-0 Knurling in the Lathe, p. 92 of 238
  • Knurling in the lathe - Knurling is done either to provide a rough surface which can be firmly gripped by the hand or for producing an ornamental effect. The handles of gaves and other tools are often knurled, and the thumb-screws used on instruments, etc., usually have knurled edges. A knurled surface consists of a series of small ridges or diamond-shaped projections, and is produced in the lathe by the use of a tool similar to the one shown in Fig 37, this being one of several different designs in common use. The knurling is done by two knurls A and B having teeth or ridges which incline to the right on one knurl and to the left on the opposite knurl, as shown by the the end view. When these two knurls are pressed against the work as the latter revolves, one knurl forms a series of left-hand ridges and the other knurl right-hand ridges, which cross and form the diamond-shaped knurling which is generally used.
  • If the surface to be knurled is wider than the knurls, the power feed of the lathe should be engaged and the knurling tool be traversed back and forth until the diamond-shaped projections are well formed. To prevent forming a double set of projections, feed the knurl in with considerable pressure at the start, then partially relieve the pressure before engaging the power feed. Use oil when knurling.
  • The knurls commonly used for lathe work have spiral teeth and ordinarily there are three classes, known as coarse, medium and fine. The medium pitch is generally used. The teeth of coarse knurls have a spiral angle of 36 degrees and the pitch of the knurled cut (measured parallel to the axis of the work) should be about 8 per inch. For medium knurls, the spiral angle is 29.5 degrees and the pitch, measured as before, is 12 per inch. For fine knurls, the spiral angle is 25.75 degrees and the pitch 20 per inch. The knurls should be about 3/4 inch in diameter and 3/8 inch wide. When made to these dimensions, coarse knurls have 34 teeth; medium, 50 teeth; and fine knurls, 80 teeth.
  • The particular tool illustrated in Fig. 37 has three pairs of knurls of coarse, medium and fine pitch. These are mounted in a revolving holder which not only serves to located the required set of knurls in the working position, but enables each knurl to bear against the surface with equal pressure. Concave knurls are sometimes used for knurling rounded edges on screw heads, etc.
  • Turning and Boring by Franklin D. Jones, 1st Ed, 1919, p. 92 of 238

Knurling and Pitch Systems

  • Diametral Pitch System (inch system only)
    • “knurling is designed to permit work blank diameters of standard fractional stock sizes ranging from 3/32inch - 1inch” (https://www.doriantool.com/wp-content/uploads/SEC-H-Knurling-Tools_LowRes.pdf p. H-11)
    • ”…good tracking (the ability of teeth to mesh as the tool penetrates the work blank in successive revolutions) is obtained by tools designed on the basis of diametral pitch instead of TPI (teeth per inch) when used with recommended work blank diameters that are multiples of 1/64“ or 1/32”, depending upon the pitch selected. This should improve the uniformity and appearance of knurling, eliminate the costly trial and error methods, reduce the failure of knurling tools and production of defective work, as well as decrease the number of tools required.“ Knurling - ANSI/ASME B94.6-1984 (R1995), p. 1
    • Diametral pitch system is derived by the number of teeth on the work divided by the theoretical work blank diameter
    • number of teeth per inch of diameter (measured on a linear inch)
    • “The four standard diametral pitches available are 64, 96, 128, and 160. The 96 and 160 diametral pitches are for blank diameters having fractional increments of 1/32”, and the 64 and 128 diametral pitches are for blank diameters having fractional diameters of 1/64”. The American Standard recommends that the use of the 64 diametral pitch should be avoided as much as possible, and for simplification of tools, preference be given to the use of 96 diametral pitch.“ (https://www.doriantool.com/wp-content/uploads/SEC-H-Knurling-Tools_LowRes.pdf p. H-14)
    • 64 DP based on 1/64 inch workpiece diameter - not recommended by Joe Pieczynski
    • 96 DP based on 1/64 inch
    • 128 DP based on 1/32 inch
    • 160 DP based on 1/32 inch
  • Circular Pitch Metric System
    • Circular pitch metric system is the distance from tooth to tooth in mm
  • Circular Pitch Inch System
    • “knurling is related to the distance between the teeth on the circumference of the work blank in inches. It is usually expressed in terms of the number of teeth per inch (TPI), although sometimes erroneously referred to as Pitch.” (https://www.doriantool.com/wp-content/uploads/SEC-H-Knurling-Tools_LowRes.pdf p. H-11)
    • based on teeth per inch (TPI) - distance between tooth to tooth
    • Circular pitch inch system is the distance from tooth to tooth, or is derived from 1” divided by the number of teeth per inch.
    • 14 TPI - coarse (number of teeth in a linear inch), so circular pitch, P = 1/14 = 0.0714“ (distance between tooth to tooth), knurl depth = 35% / TPI
    • 21 TPI - medium, P = 1/21 = 0.0476”
    • 33 TPI - fine, P = 1/33 = 0.0303“
    • Other types
      • Circular Pitch of 20TPI is 1/20 = 0.050”
      • Knurling Depth is 0.050“ x 35% = 0.0175” per side
        • Knurl Depth = TPI/35% = 0.0175“ per side
  • References

Knurling Videos

Dorian Tool - Knurling

  • Dorian Tool International
    • Aaron Elberson, aelberson@doriantool.com, cell 713-377-0944, direct 979-398-3209
    • 615 CR 219, East Bernard TX 77435
  • Dorian Tool - Knurling Support
  • Dorian Tool - cutting speed
  • Straddle Style Knurl Tool
    • Figure 1-0 Dorian W109-3T-2-4
  • Before Knurl Diameter = 0.8885” closest to 0.9“ on NIMS workpiece
    • depth of tool per side = 0.016”
  • Figure 1-0 Dorian Knurling Tool

Knurling Tools

Knurl Calculations for Diametral Pitch

  • DP = Diametral Pitch of Knurl
    • DP = Nt / Dnt
  • Nt = number of teeth on knurl
  • Dnt = nominal diameter of knurl
  • Reference
    • Machinery's Handbook 28th Edition by Industrial Press, p. 1211

Knurl Calculations for Cylindrical Knurls

Perfect Diamond Knurl by Jeff Jensen

  1. Initial Diameter (∅init) of work piece to be knurled
  2. TPI of knurl wheel (medium knurl uses 21 TPI)
  3. Traverse circular Pitch, PT = 1 / (TPI cos 30°) for diamond knurls typical helix angle is 30°
  4. Number of Knurls (Real) = π ∅init / PT
    1. Multiple or Integer = round(Real)
      1. round down if workpiece diameter cannot be increased, say in the case it has already been machined
  5. new or revised Diameter (∅rev) of work piece = Integer * PT / π
    1. if this Diameter, ∅rev is out of tolerance, then will have to use a different knurl wheel (TPI) such as course or fine
  • Reference
    • “Knurled diameters and the circular pitch (1/TPI) of the knurl are related. The circumference of the work blank should be an approximate multiple of the circular pitch for straight knurling and transverse circular pitch (Pt) for diagonal and diamond knurling. Blank diameters vary with the circular pitch of the knurling selected, and should only be specified after the proper diameter of blank is determined by trial and error.” (Dorian International Tool - Knurling Tools for Cutting and Forming p. H-17)
    • Figure 1-0 Dorian Knurling Tool Transverse Circular Pitch
    • MSC Direct Knurl Wheel
      • Figure 1-0 MSC Direct - Knurl Wheel

Perfect Knurls

  • Goal - achieve good tracking (the ability of teeth to mesh as the tool penetrates the work blank in successive revolutions) (Machinery's Handbook, 28th, p. 1210), improve uniformity and appearance of knurling.
  • 1.
  • 1. Determine the diametral pitch of knurl die. Either 64 or 128 when work blank diameters are multiples of 1/64 inch. Use 96 or 160 diametral pitch when work blank diameters are in multiples of 1/32 inch.
    • 0.900” +/- 1/32 (0.03125) for NIMS knurl diameter
      • Min = 0.86875“
      • Max = 0.93125”
    • 55/64“ = 0.8594” out of spec
    • 56/64“ = 0.8750”
    • 57/64“ = 0.8906”
    • 58/64“ = 0.9063”
    • 59/64“ = 0.9219”
    • 60/64“ = 0.9375” out of spec
    • Figure 1-0 Dorian SW4L-25
  • 2. Lathe spindle speed (RPM)
    • “Knurling is ordinarily performed at the same speeds used as cutting operations. Use the SFM used for high speed and cobalt tool bits to calculate speeds and feeds. However, where spindle speeds can be reduced without loss of production, it is recommended that spindle speeds be lowered as much as possible to increase knurl life.” (Dorian Tool - Knurling Tools for Cutting & Forming p. H-10)

Knurl - Machine Shop Trade Secrets

  • “A proper diameter to knurl is any diameter that is a multiple of the spacing or distance between the teeth of a knurling tool divided by Pi π (3.14159). The relationship is the same whether the knurl is a diamond or a straight knurl. However, the spacing of the teeth of a diamond knurl must be measured along the axis of the part or roller for the relationship to hold true.” ([Harvey 2004, p.190])
  • Let's do an example: Suppose you want to impress a diamond knurl on a one inch diameter shaft. Suppose also that the spacing or distance between each tooth of the knurling tool measured along the axis of the roller is approximately .060“. You can measure the spacing with calipers. The measurement is not extremely critical in that ultimately your final diameter will be determined by trial and error. However, the measurement will give you a decent starting point. According to the above relationship, if we divide .060 by Pi π (3.14159) we get .019. Accordingly, any multiple of .019 should give you a diameter that would give you a perfect knurl. For example: .019 times an arbitrary number such as 40 equals .760. In theory then, if you turned a shaft to .760” you would be able to create a perfect knurl. However, since we want to knurl a shaft that is approximately one inch in diameter we have to find a multiple of .019 that gets us close to one inch. After a little trial and error and playing around on a calculator we find that .019 times 52 equals .988 which is close to one inch. .988 then would be a good theoretical starting point.
  • In practice though and from experience the chances of getting a perfect knurl on the .988 shaft diameter are not great. The error happens as a result of an imperfect measurement made between the teeth of the knurling tool which is no big deal anyhow because ultimately you are going to sneak up on a usable diameter. Begin by machining the part about .010“ larger than the calculated diameter. Let's proceed.”
  • References

Knurl Training Product

  • Product
    • PDF handout
    • Excel Spreadsheet
      • add more Knurl TPI
    • Phone App
    • Webpage
    • How To Training Materials
  • Hurdle #1 - Perfect Diameter
  • Hurdle #2 - Depth of Knurl
  • Hurdle #3 - Speed and Feed
    • Based on Different Materials
      • ASTM A36
      • Steel 1018
      • Steel 12L14
      • Steel 4140 TGP (Turned, Ground, Polished)
      • Stainless Steel
      • Aluminum
      • Delren Plastic

Model a Knurl

Winding Coils

Tapering

Lathe Cutting Tools

High Speed Steel (HSS)

  • Imported M2 High Speed Steel
  • American made T-15 High Speed Steel from A. R. Warner Co.
  • Figure 1-0 Schematic illustration of a right-hand cutting tool. Manufacturing Engineering by Kalpakjian
  • Figure 1-0 Terms Applied to Single-point Turning Tools from Machinery's Handbook, 27th Edition, p. 749
  • Figure 1-0 Cutter Bit Nomenclature, Machining Fundamentals, 9th Edition, p. 228

Carbide Tipped Tools

  • Have the point of the cutting tool face you, if it cuts on the right, then it is a right handed cutting tool, if it cuts on the left, then left handed
    • Style A - straight shank, 0° side cutting edge angle (SCEA)
      • Figure 1-0 American National Standard Style A Carbide Tipped Tool, Machinery's Handbook, 27th Edition, p. 767
    • Style B - 15° side cutting edge angle (SCEA)
      • Figure 1-0 American National Standard Style B Carbide Tipped Tool, Machinery's Handbook, 27th Edition, p. 768
    • Style C and E - 15° side cutting edge angle (SCEA)
      • Figure 1-0 American National Standard Style C and E Carbide Tipped Tool, Machinery's Handbook, 27th Edition, p. 769-770

Carbide Insert Tools

Selecting a Lathe

  • Need to Have
  1. Automatic longitudinal feed - need to make threads and creating a smooth finish when turning
  • Nice to Have
  1. Automatic Crossfeed - helpful when parting and facing your workpiece
  • Beginner's Guide to the Metal Lathe by Biscuit Studios
    • Smithy Gear Drive Lathe 12 x 37 - this means diameter is 12“ (swing over bed) and the distance between head stock and tail stock is 37” (distance between centers)

Lathe Workflow

  • Figure 1-0 Lathe Workflow on a short pipe, Toolingu.com, Engine Lathe Operation 225 - Lesson 12 of 23 - Making a Sample Part

Lathe Machining Tools

Ganesh GT-1640S Lathe

  • Speeds (RPM) - 30, 55, 70, 95, 160, 200, 325, 540, 700, 1000, 1600, 2000
  • Feeds

Setting 1 2 3 4 5 6 7 8
IATX .0012 .0014 .0015 .0016 .0017 .0018 .0020 .0022
IASX .0024 .0028 .0030 .0032 .0034 .0036 .0040 .0044
IARX .0048 .0056 .0060 .0064 .0068 .0072 .0080 .0088
IIAJX .0096 .0112 .0120 .0128 .0136 .0144 .0160 .0176
IIARX .0192 .0224 .0240 .0256 .0272 .0288 .0320 .0352

Help

Makerspace

  • TechShop
  • Sheetmetal Parts
    • Protocase
  • eMachineShop
  • Fictiv.com
  • Xometry.com
  • LACI
  • Kickstarter

Being a Machinist

  • It Never Rains Oil

Machining Companies

CNC Software

Jobs

- 5 years minimum experience required - High school diploma, GED, or graduate of a technical school - Ability to setup programs and make offset adjustments - Knowledge of basic machining practices - Understanding of G-Code programming - Ability to read, understand blueprints and GD and T required - Ability to use inspection equipment and inspection techniques - Must have own tools - Understanding of AS9100 and ISO quality requirements

  • Wiseco Performance Products
    • CNC Machinists. We need Machinists to do set ups and/or operate our 125 CNC lathes and mills. All skill levels welcome! H.S. Diploma or GED, 1+ years' experience as a CNC machine operator or setup. Ability to read micrometers and calipers required. Reliable, dependable attendance and a strong work ethic a must!
    • CNC Programmer. If you have 5+ years programming Mazak machines and Mazatrol controls using MasterCam, can import solids, and create multi-axis programs, we offer you a very handsome hourly rate of \$24-\$30/hour depending on your skill level, speed, and accuracy. This is not X,Y, Z programming. Once your programming is complete, you will get to run test parts and check your work. High School Diploma or GED, 5+ years’ verifiable programming history, strong work ethic, positive, team attitude and a willingness to learn. Regular, reliable, dependable attendance is a must!
    • Contact Us Email on 21 Sept 2014. Hello Wiseco,

I would like your recommendation on a wiseco high performance piston that I will have my students recreate, that is (draw in Autodesk Inventor, print on a 3D printer, use as a pattern to sand cast out of aluminum, and machine on a lathe and mill) and use in a steam engine. I need a piston that can fit in a 5“x5”x5“ box.

Will you please let me know who I could discuss this idea in more detail with and what the cost will be.

Thanks,

Jeff Jensen Teacher Bonanza High School 6665 W Del Rey Ave Las Vegas NV 89146 mobile: 702-327-9294

Education

California Schools and Colleges

Carolina Schools

Idaho Schools and Colleges

Utah Schools and Colleges

Washington College

Florida Schools and Colleges

Supplies and Materials

Plastics

CCSD High Schools

  • Southwest Career Technical Academy (SWCTA) owns a Jet GH-1460ZX lathe
    • Figure 1-0 JET Lathe owned by SWCTA
  • Southwest Career Technical Academy (SWCTA) owns an ACRA milling machine
    • Figure 1-0 ACRA Milling Machine owned by SWCTA

MIT Machine Shop Videos by Erik Vaaler

  • Machine Shop 8 Lathe 1 - lathe components at setup axes and feeds, turning tools, turing and facing, cutting off a part
  • Machine Shop 9 Lathe 2 - tapping, boring, knurlin, cutting tapers with the compound, turning shafts use of live center, single point <b>thread turning</b>
  • Machine Shop 10 Lathe 3 - lathe chuck, arbors, turning between centers, face plate irregular shapes and face plate thin materials

Toms Techniques

  • Turning a Diameter to size on the Lathe

ToolingU.com

  • login jjjensen password normal
  • Engine Lathe Operation 225 (150115 and 150205)
  • Krista Maurer, Business Development - ToolingU-SME, email krista.maurer@toolingu.com, 3615 Superior Ave East, Buidling 44, 6th Floor Cleveland, OH 44114, Office: 216-706-6647 l Fax: 216-706-6601

Old School Machine Shop by Marshall Berg

Ganesh Machinery

  • Derek Stanton, Regional Manager, Mobile: 818-518-4013, email: derek@ganeshmachinery.com, offers 15% discount to schools.
    • Support - luis@ganeshmachinery.com
  • GMV-2 Manual Knee Mill - cost about \$16,000
  • csi.edu

Kennametal

  • Jason (left company - Randy Kopka, Senior Analyst), Customer Application Support, na.techsupport@kennametal.com, 800-835-3668
  • Tool Holder Size, Square Shank
  • Right Hand, On Center or Left Hand

Grizzly Industrial

Sherline and IMService

Enco

Harbor Freight

Smithy Industries

  1. Lathe only produces three types of cuts:
    1. Turning - cutting tool is moved parallel to the lathe axis, removes material from the outside diameter of the work piece
    2. Facing - cutting tool is moved perpendicular to the lathe axis, removes material from the end or edge of the part
    3. Boring - cutting tool removes material from the inside diameter of the work piece
    4. These cuts can then be used for drilling, cutting tapers, threading, grinding, plunge cuts
  • 1.1 Machine Tool Basics - Intro to Lathe Operations on Smithy Granite 3-in-1 combo
  • 1.2 Machine Tool Basics - Lathe Workholding - Smithy Granite 3-in-1
    • shows flaceplate, rule of thumb need to use the lathe center with a live center (rotating point) in the tail stock to hold the opposite end if the length of the work piece is greater than 3x the diameter, or use a steady rest or a follow rest
  • 1.3 Machine Tool Basics - Lathe Cutting Tools
  • 1.4 Machine Tool Basics - Lathe Controls - Smithy Granite 3-in-1
  • 2.1 Machine Tool Basics - Milling Machine Operations - Smithy Granite 3-in-1
  • 2.2 Machine Tool Basics - Mill Cuttin Tools - Smithy Granite 3-in-1
    • Face, Flycutter - produce excellent flat finish
  • 2.3 Machine Tool Basics - Mill Workholding - Smithy Granite 3-in-1
  • 2.4 Machine Tool Basics - Milling Controls - Smithy Granite 3-in-1
  • 3.1 Machine Tool Basics - Tool Maintenance - Smithy Granite 3-in-1

Gunsmith

Gunsmith Schools

Gun Manufactures

NIMS Certification

Turning I ( Between Centers)

Navigation

Civil Engineering Engineering - Computer Engineering - Electrical Mechanical Engineering

Print/export
QR Code
QR Code engineer-mechanical:machining (generated for current page)