View source for Myford lathe/drill and thread charts

Handy drill and thread charts for use with the lathe.<br/>
Remember for all drilling operations to use a suitable RPM and drill fluid.<br/>

==Drill RPM calculations==

Steel<br/>
Aluminium<br/>
Brass<br/>

==Center Drills==
For any drilling operation on the lathe the Center drill is used first to make the small accurate pilot that the next drill will follow.<br/>
They are also use for drilling the required hole when using the live or dead centres.<br/>
Use the Highest RPM setting on the lathe!<br/>
General rule of thumb is to drill no more than 2/3 up the 60 degree angle<br/>
We have 4 Center drill sizes to chose form, BS1 to BS4<br/>
For general piloting work the BS3 or BS4 are recommended as the smaller ones are easy to snap.<br/>

When supporting work with a live or dead centre lookup the work diameter in the following table to determine the correct drill size and size of the hole needed.<br/>

{| class="wikitable"
! style="text-align: right; font-weight:bold; background-color:#c0c0c0;" | Gauge
! style="font-weight:bold; background-color:#c0c0c0;" | Size (Inches)
! style="text-align: center; font-weight:bold; background-color:#c0c0c0;" | Size (mm)
|-
| style="text-align: right; background-color:#efefef;" | BS1
| 1⁄8 in
| style="text-align: center;" | 3.175 mm
|-
| style="text-align: right; background-color:#efefef;" | BS2
| 3⁄16 in
| style="text-align: center;" | 4.763 mm
|-
| style="text-align: right; background-color:#efefef;" | BS3
| 1⁄4 in
| style="text-align: center;" | 6.350 mm
|-
| style="text-align: right; background-color:#efefef;" | BS4
| 5⁄16 in
| style="text-align: center;" | 7.938 mm
|-
| style="text-align: right; background-color:#efefef;" | BS5
| 7⁄16 in
| style="text-align: center;" | 11.113 mm
|-
| style="text-align: right; background-color:#efefef;" | BS5A
| 1⁄2 in
| style="text-align: center;" | 12.700 mm
|-
| style="text-align: right; background-color:#efefef;" | BS6
| 5⁄8 in
| style="text-align: center;" | 15.875 mm
|-
| style="text-align: right; background-color:#efefef;" | BS7
| 3⁄4 in
| style="text-align: center;" | 19.050 mm
|}

==Threading Charts==

===Metric===
The Hackspace has a tap and die set with the following metric coarse sizes

M3 M4 M5 M6 M8 M10 M12

For tapping internal threads use the chart below to select the correct drill size and if needed clearance size for the tap.

[[File:Metric Threads.PNG|thumbnail|Threading Diagram]]

{| class="wikitable"
!  style="font-weight:bold; font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | Nominal Diameter
!  style="font-weight:bold; font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | Pitch
!  style="font-weight:bold; font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | Root Radius
!  style="font-weight:bold; font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | Pitch Diameter
!  colspan="2" style="font-weight:bold; font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | Minor Diameter
!  colspan="2" style="font-weight:bold; font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | Thread Height
!  style="font-weight:bold; font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | Drill Diameter
|-

|-
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | d = D
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | P
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | r
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | d2=D2
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | d3
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | D1
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | h3
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | H1
| style="font-family:Verdana, Geneva, sans-serif !important;; background-color:#036400; color:#ffffff;" | mm
|-
| style="background-color:#c0c0c0;" | M 1.00
| style="background-color:#efefef;" | 0.25
| style="background-color:#efefef;" | 0.036
| style="background-color:#efefef;" | 0.838
| style="background-color:#efefef;" | 0.693
| style="background-color:#efefef;" | 0.729
| style="background-color:#efefef;" | 0.153
| style="background-color:#efefef;" | 0.135
| style="background-color:#efefef;" | 0.75
|-
| style="background-color:#c0c0c0;" | M 1.10
| style="background-color:#efefef;" | 0.25
| style="background-color:#efefef;" | 0.036
| style="background-color:#efefef;" | 0.938
| style="background-color:#efefef;" | 0.793
| style="background-color:#efefef;" | 0.829
| style="background-color:#efefef;" | 0.153
| style="background-color:#efefef;" | 0.135
| style="background-color:#efefef;" | 0.85
|-
| style="background-color:#c0c0c0;" | M 1.20
| style="background-color:#efefef;" | 0.25
| style="background-color:#efefef;" | 0.036
| style="background-color:#efefef;" | 1.038
| style="background-color:#efefef;" | 0.893
| style="background-color:#efefef;" | 0.929
| style="background-color:#efefef;" | 0.153
| style="background-color:#efefef;" | 0.135
| style="background-color:#efefef;" | 0.95
|-
| style="background-color:#c0c0c0;" | M 1.40
| style="background-color:#efefef;" | 0.3
| style="background-color:#efefef;" | 0.043
| style="background-color:#efefef;" | 1.205
| style="background-color:#efefef;" | 1.032
| style="background-color:#efefef;" | 1.075
| style="background-color:#efefef;" | 0.184
| style="background-color:#efefef;" | 0.162
| style="background-color:#efefef;" | 1.1
|-
| style="background-color:#c0c0c0;" | M 1.60
| style="background-color:#efefef;" | 0.35
| style="background-color:#efefef;" | 0.051
| style="background-color:#efefef;" | 1.373
| style="background-color:#efefef;" | 1.171
| style="background-color:#efefef;" | 1.221
| style="background-color:#efefef;" | 0.215
| style="background-color:#efefef;" | 0.189
| style="background-color:#efefef;" | 1.25
|-
| style="background-color:#c0c0c0;" | M 1.80
| style="background-color:#efefef;" | 0.35
| style="background-color:#efefef;" | 0.051
| style="background-color:#efefef;" | 1.573
| style="background-color:#efefef;" | 1.371
| style="background-color:#efefef;" | 1.421
| style="background-color:#efefef;" | 0.215
| style="background-color:#efefef;" | 0.189
| style="background-color:#efefef;" | 1.45
|-
| style="background-color:#c0c0c0;" | M 2.00
| style="background-color:#efefef;" | 0.4
| style="background-color:#efefef;" | 0.058
| style="background-color:#efefef;" | 1.74
| style="background-color:#efefef;" | 1.509
| style="background-color:#efefef;" | 1.567
| style="background-color:#efefef;" | 0.245
| style="background-color:#efefef;" | 0.217
| style="background-color:#efefef;" | 1.6
|-
| style="background-color:#c0c0c0;" | M 2.20
| style="background-color:#efefef;" | 0.45
| style="background-color:#efefef;" | 0.065
| style="background-color:#efefef;" | 1.908
| style="background-color:#efefef;" | 1.648
| style="background-color:#efefef;" | 1.713
| style="background-color:#efefef;" | 0.276
| style="background-color:#efefef;" | 0.244
| style="background-color:#efefef;" | 1.75
|-
| style="background-color:#c0c0c0;" | M 2.50
| style="background-color:#efefef;" | 0.45
| style="background-color:#efefef;" | 0.065
| style="background-color:#efefef;" | 2.208
| style="background-color:#efefef;" | 1.948
| style="background-color:#efefef;" | 2.013
| style="background-color:#efefef;" | 0.276
| style="background-color:#efefef;" | 0.244
| style="background-color:#efefef;" | 2.05
|-
| style="background-color:#c0c0c0;" | M 3.00
| style="background-color:#efefef;" | 0.5
| style="background-color:#efefef;" | 0.072
| style="background-color:#efefef;" | 2.675
| style="background-color:#efefef;" | 2.387
| style="background-color:#efefef;" | 2.459
| style="background-color:#efefef;" | 0.307
| style="background-color:#efefef;" | 0.271
| style="background-color:#efefef;" | 2.5
|-
| style="background-color:#c0c0c0;" | M 3.50
| style="background-color:#efefef;" | 0.6
| style="background-color:#efefef;" | 0.087
| style="background-color:#efefef;" | 3.11
| style="background-color:#efefef;" | 2.764
| style="background-color:#efefef;" | 2.85
| style="background-color:#efefef;" | 0.368
| style="background-color:#efefef;" | 0.325
| style="background-color:#efefef;" | 2.9
|-
| style="background-color:#c0c0c0;" | M 4.00
| style="background-color:#efefef;" | 0.7
| style="background-color:#efefef;" | 0.101
| style="background-color:#efefef;" | 3.545
| style="background-color:#efefef;" | 3.141
| style="background-color:#efefef;" | 3.242
| style="background-color:#efefef;" | 0.429
| style="background-color:#efefef;" | 0.379
| style="background-color:#efefef;" | 3.3
|-
| style="background-color:#c0c0c0;" | M 4.50
| style="background-color:#efefef;" | 0.75
| style="background-color:#efefef;" | 0.108
| style="background-color:#efefef;" | 4.013
| style="background-color:#efefef;" | 3.58
| style="background-color:#efefef;" | 3.688
| style="background-color:#efefef;" | 0.46
| style="background-color:#efefef;" | 0.406
| style="background-color:#efefef;" | 3.8
|-
| style="background-color:#c0c0c0;" | M 5.00
| style="background-color:#efefef;" | 0.8
| style="background-color:#efefef;" | 0.115
| style="background-color:#efefef;" | 4.48
| style="background-color:#efefef;" | 4.019
| style="background-color:#efefef;" | 4.134
| style="background-color:#efefef;" | 0.491
| style="background-color:#efefef;" | 0.433
| style="background-color:#efefef;" | 4.2
|-
| style="background-color:#c0c0c0;" | M 6.00
| style="background-color:#efefef;" | 1
| style="background-color:#efefef;" | 0.144
| style="background-color:#efefef;" | 5.35
| style="background-color:#efefef;" | 4.773
| style="background-color:#efefef;" | 4.917
| style="background-color:#efefef;" | 0.613
| style="background-color:#efefef;" | 0.541
| style="background-color:#efefef;" | 5
|-
| style="background-color:#c0c0c0;" | M 7.00
| style="background-color:#efefef;" | 1
| style="background-color:#efefef;" | 0.144
| style="background-color:#efefef;" | 6.35
| style="background-color:#efefef;" | 5.773
| style="background-color:#efefef;" | 5.917
| style="background-color:#efefef;" | 0.613
| style="background-color:#efefef;" | 0.541
| style="background-color:#efefef;" | 6
|-
| style="background-color:#c0c0c0;" | M 8.00
| style="background-color:#efefef;" | 1.25
| style="background-color:#efefef;" | 0.18
| style="background-color:#efefef;" | 7.188
| style="background-color:#efefef;" | 6.466
| style="background-color:#efefef;" | 6.647
| style="background-color:#efefef;" | 0.767
| style="background-color:#efefef;" | 0.677
| style="background-color:#efefef;" | 6.8
|-
| style="background-color:#c0c0c0;" | M 9.00
| style="background-color:#efefef;" | 1.25
| style="background-color:#efefef;" | 0.18
| style="background-color:#efefef;" | 8.188
| style="background-color:#efefef;" | 7.466
| style="background-color:#efefef;" | 7.647
| style="background-color:#efefef;" | 0.767
| style="background-color:#efefef;" | 0.677
| style="background-color:#efefef;" | 7.8
|-
| style="background-color:#c0c0c0;" | M 10.00
| style="background-color:#efefef;" | 1.5
| style="background-color:#efefef;" | 0.217
| style="background-color:#efefef;" | 9.026
| style="background-color:#efefef;" | 8.16
| style="background-color:#efefef;" | 8.376
| style="background-color:#efefef;" | 0.92
| style="background-color:#efefef;" | 0.812
| style="background-color:#efefef;" | 8.5
|-
| style="background-color:#c0c0c0;" | M 11.00
| style="background-color:#efefef;" | 1.5
| style="background-color:#efefef;" | 0.217
| style="background-color:#efefef;" | 10.026
| style="background-color:#efefef;" | 9.16
| style="background-color:#efefef;" | 9.376
| style="background-color:#efefef;" | 0.92
| style="background-color:#efefef;" | 0.812
| style="background-color:#efefef;" | 9.5
|-
| style="background-color:#c0c0c0;" | M 12.00
| style="background-color:#efefef;" | 1.75
| style="background-color:#efefef;" | 0.253
| style="background-color:#efefef;" | 10.863
| style="background-color:#efefef;" | 9.853
| style="background-color:#efefef;" | 10.106
| style="background-color:#efefef;" | 1.074
| style="background-color:#efefef;" | 0.947
| style="background-color:#efefef;" | 10.2
|-
| style="background-color:#c0c0c0;" | M 14.00
| style="background-color:#efefef;" | 2
| style="background-color:#efefef;" | 0.289
| style="background-color:#efefef;" | 12.701
| style="background-color:#efefef;" | 11.546
| style="background-color:#efefef;" | 11.835
| style="background-color:#efefef;" | 1.227
| style="background-color:#efefef;" | 1.083
| style="background-color:#efefef;" | 12
|-
| style="background-color:#c0c0c0;" | M 16.00
| style="background-color:#efefef;" | 2
| style="background-color:#efefef;" | 0.289
| style="background-color:#efefef;" | 14.701
| style="background-color:#efefef;" | 13.546
| style="background-color:#efefef;" | 13.835
| style="background-color:#efefef;" | 1.227
| style="background-color:#efefef;" | 1.083
| style="background-color:#efefef;" | 14
|-
| style="background-color:#c0c0c0;" | M 18.00
| style="background-color:#efefef;" | 2.5
| style="background-color:#efefef;" | 0.361
| style="background-color:#efefef;" | 16.376
| style="background-color:#efefef;" | 14.933
| style="background-color:#efefef;" | 15.394
| style="background-color:#efefef;" | 1.534
| style="background-color:#efefef;" | 1.353
| style="background-color:#efefef;" | 15.5
|-
| style="background-color:#c0c0c0;" | M 20.00
| style="background-color:#efefef;" | 2.5
| style="background-color:#efefef;" | 0.361
| style="background-color:#efefef;" | 18.376
| style="background-color:#efefef;" | 16.933
| style="background-color:#efefef;" | 17.294
| style="background-color:#efefef;" | 1.534
| style="background-color:#efefef;" | 1.353
| style="background-color:#efefef;" | 17.5
|-
| style="background-color:#c0c0c0;" | M 22.00
| style="background-color:#efefef;" | 2.5
| style="background-color:#efefef;" | 0.361
| style="background-color:#efefef;" | 20.376
| style="background-color:#efefef;" | 18.933
| style="background-color:#efefef;" | 19.294
| style="background-color:#efefef;" | 1.534
| style="background-color:#efefef;" | 1.353
| style="background-color:#efefef;" | 19.5
|-
| style="background-color:#c0c0c0;" | M 24.00
| style="background-color:#efefef;" | 3
| style="background-color:#efefef;" | 0.433
| style="background-color:#efefef;" | 22.051
| style="background-color:#efefef;" | 20.319
| style="background-color:#efefef;" | 20.752
| style="background-color:#efefef;" | 1.84
| style="background-color:#efefef;" | 1.624
| style="background-color:#efefef;" | 21
|-
| style="background-color:#c0c0c0;" | M 27.00
| style="background-color:#efefef;" | 3
| style="background-color:#efefef;" | 0.433
| style="background-color:#efefef;" | 25.051
| style="background-color:#efefef;" | 23.319
| style="background-color:#efefef;" | 23.752
| style="background-color:#efefef;" | 1.84
| style="background-color:#efefef;" | 1.624
| style="background-color:#efefef;" | 24
|-
| style="background-color:#c0c0c0;" | M 30.00
| style="background-color:#efefef;" | 3.5
| style="background-color:#efefef;" | 0.505
| style="background-color:#efefef;" | 27.727
| style="background-color:#efefef;" | 25.706
| style="background-color:#efefef;" | 26.211
| style="background-color:#efefef;" | 2.147
| style="background-color:#efefef;" | 1.894
| style="background-color:#efefef;" | 26.5
|-
| style="background-color:#c0c0c0;" | M 33.00
| style="background-color:#efefef;" | 3.5
| style="background-color:#efefef;" | 0.505
| style="background-color:#efefef;" | 30.727
| style="background-color:#efefef;" | 28.706
| style="background-color:#efefef;" | 29.211
| style="background-color:#efefef;" | 2.147
| style="background-color:#efefef;" | 1.894
| style="background-color:#efefef;" | 29.5
|-
| style="background-color:#c0c0c0;" | M 36.00
| style="background-color:#efefef;" | 4
| style="background-color:#efefef;" | 0.577
| style="background-color:#efefef;" | 33.402
| style="background-color:#efefef;" | 31.093
| style="background-color:#efefef;" | 31.67
| style="background-color:#efefef;" | 2.454
| style="background-color:#efefef;" | 2.165
| style="background-color:#efefef;" | 32
|-
| style="background-color:#c0c0c0;" | M 39.00
| style="background-color:#efefef;" | 4
| style="background-color:#efefef;" | 0.577
| style="background-color:#efefef;" | 36.402
| style="background-color:#efefef;" | 34.093
| style="background-color:#efefef;" | 34.67
| style="background-color:#efefef;" | 2.454
| style="background-color:#efefef;" | 2.165
| style="background-color:#efefef;" | 35
|-
| style="background-color:#c0c0c0;" | M 42.00
| style="background-color:#efefef;" | 4.5
| style="background-color:#efefef;" | 0.65
| style="background-color:#efefef;" | 39.077
| style="background-color:#efefef;" | 36.479
| style="background-color:#efefef;" | 37.129
| style="background-color:#efefef;" | 2.76
| style="background-color:#efefef;" | 2.436
| style="background-color:#efefef;" | 37.5
|-
| style="background-color:#c0c0c0;" | M 45.00
| style="background-color:#efefef;" | 4.5
| style="background-color:#efefef;" | 0.65
| style="background-color:#efefef;" | 42.077
| style="background-color:#efefef;" | 39.479
| style="background-color:#efefef;" | 40.129
| style="background-color:#efefef;" | 2.76
| style="background-color:#efefef;" | 2.436
| style="background-color:#efefef;" | 40.5
|-
| style="background-color:#c0c0c0;" | M 48.00
| style="background-color:#efefef;" | 5
| style="background-color:#efefef;" | 0.722
| style="background-color:#efefef;" | 44.752
| style="background-color:#efefef;" | 41.866
| style="background-color:#efefef;" | 42.857
| style="background-color:#efefef;" | 3.067
| style="background-color:#efefef;" | 2.706
| style="background-color:#efefef;" | 43
|-
| style="background-color:#c0c0c0;" | M 52.00
| style="background-color:#efefef;" | 5
| style="background-color:#efefef;" | 0.722
| style="background-color:#efefef;" | 48.752
| style="background-color:#efefef;" | 45.866
| style="background-color:#efefef;" | 46.587
| style="background-color:#efefef;" | 3.067
| style="background-color:#efefef;" | 2.706
| style="background-color:#efefef;" | 47
|-
| style="background-color:#c0c0c0;" | M 56.00
| style="background-color:#efefef;" | 5.5
| style="background-color:#efefef;" | 0.794
| style="background-color:#efefef;" | 52.428
| style="background-color:#efefef;" | 49.252
| style="background-color:#efefef;" | 50.046
| style="background-color:#efefef;" | 3.374
| style="background-color:#efefef;" | 2.977
| style="background-color:#efefef;" | 50.5
|-
| style="background-color:#c0c0c0;" | M 60.00
| style="background-color:#efefef;" | 5.5
| style="background-color:#efefef;" | 0.794
| style="background-color:#efefef;" | 56.428
| style="background-color:#efefef;" | 53.252
| style="background-color:#efefef;" | 54.046
| style="background-color:#efefef;" | 3.374
| style="background-color:#efefef;" | 2.977
| style="background-color:#efefef;" | 54.5
|-
| style="background-color:#c0c0c0;" | M 64.00
| style="background-color:#efefef;" | 6
| style="background-color:#efefef;" | 0.866
| style="background-color:#efefef;" | 60.103
| style="background-color:#efefef;" | 56.639
| style="background-color:#efefef;" | 57.505
| style="background-color:#efefef;" | 3.681
| style="background-color:#efefef;" | 3.248
| style="background-color:#efefef;" | 58
|-
| style="background-color:#c0c0c0;" | M 68.00
| style="background-color:#efefef;" | 6
| style="background-color:#efefef;" | 0.866
| style="background-color:#efefef;" | 64.103
| style="background-color:#efefef;" | 60.639
| style="background-color:#efefef;" | 61.505
| style="background-color:#efefef;" | 3.681
| style="background-color:#efefef;" | 3.248
| style="background-color:#efefef;" | 62
|}

Credit for table: www.tribology-abc.com

For the external threads turn down the work piece to the major diameter.<br/>
It is advisable to add a slight chamfer to the right end of the work, to just under the thread minor diameter using the left edge of the cutting tool.

===British Standard Whitworth (BSW)===

==Reference Sites==
http://www.tribology-abc.com/calculators/metric-iso.htm

[[Category:Tools_and_Equipment]]