Engineer's Data Charts
A selection of charts useful to engineers.
Drills Chart
Tapping Drills
Buttons
Forms
Tables
Common Abreviations
Tapping and Clearance Drills
BSW
BSF
Whitworth Coarse Thread (BSW)
Nominal Size
T.P.I.
Basic Depth of thread
Basic Major Ø
Basic Effective Ø
Basic Minor Ø
Tapping Drill Size (mm)
Clearance Drill Size (mm)
1/16
60
0.0107
0.0625
0.0518
0.0411
1.20
1.65
3/32
48
0.0133
0.0938
0.0805
0.0672
1.85
2.50
1/8
40
0.0160
0.1250
0.1090
0.0930
2.55
3.30
5/32
32
0.0200
0.1562
0.1362
0.1162
3.20
4.10
3/16
24
0.0267
0.1875
0.1608
0.1341
3.70
4.90
7/32
24
0.0267
0.2188
0.1921
0.1654
4.50
5.70
1/4
20
0.0320
0.2500
0.2180
0.1860
5.10
6.50
5/16
18
0.0356
0.3125
0.2769
0.2413
6.50
8.10
3/8
16
0.0400
0.3750
0.3350
0.2950
7.90
9.70
7/16
14
0.0457
0.4375
0.3918
0.3461
9.30
11.30
1/2
12
0.0534
0.5000
0.4466
0.3932
10.50
13.00
9/16
12
0.0534
0.5625
0.5091
0.4557
12.10
14.50
5/8
11
0.0582
0.6250
0.5668
0.5086
13.50
16.25
11/16
11
0.0582
0.6875
0.6293
0.5711
15.00
17.75
3/4
10
0.0640
0.7500
0.6860
0.6220
16.25
19.25
13/16
10
0.0640
0.8125
0.7485
0.6845
18.00
21.00
7/8
9
0.0711
0.8750
0.8039
0.7328
19.25
22.50
15/16
9
0.0711
0.9375
0.8664
0.7953
20.75
24.00
1
8
0.0800
1.0000
0.9200
0.8400
22.00
25.75
1 1/8
7
0.0915
1.1250
1.0335
0.9420
24.75
29.00
1 1/4
7
0.0915
1.2500
1.1585
1.0670
28.00
32.00
1 3/8
6
0.1067
1.3750
1.2683
1.1616
30.25
35.50
1 1/2
6
0.1067
1.5000
1.3933
1.2866
33.50
38.50
1 5/8
5
0.1281
1.6250
1.4969
1.3688
35.50
41.50
1 3/4
5
0.1281
1.7500
1.6219
1.4938
39.00
45.00
1 7/8
4.5
0.1423
1.8750
1.7327
1.5904
41.50
48.00
2
4.5
0.1423
2.0000
1.8577
1.7154
44.50
51.00
2 1/4
4
0.1601
2.2500
2.0899
1.9298
51.00
58.00
2 1/2
4
0.1601
2.5000
2.3399
2.1798
57.00
64.00
2 3/4
70.00
3
77.00
British Standard Fine Thread (BSF)
Nominal Size
T.P.I.
Basic Depth of thread
Basic Major Ø
Basic Effective Ø
Basic Minor Ø
Tapping Drill Size (mm)
Clearance Drill Size (mm)
1/16
1.65
3/32
2.50
1/8
3.30
5/32
4.10
3/16
32
0.0200
0.1875
0.1675
0.1475
4.00
4.90
7/32
28
0.0229
0.2188
0.1959
0.1730
4.60
5.70
1/4
26
0.0246
0.2500
0.2254
0.2008
5.30
6.50
5/16
22
0.0291
0.3125
0.2834
0.2543
6.80
8.10
3/8
20
0.0320
0.3750
0.3430
0.3110
8.30
9.70
7/16
18
0.0356
0.4375
0.4019
0.3663
9.70
11.30
1/2
16
0.0400
0.5000
0.4600
0.4200
11.10
13.00
9/16
16
0.4000
0.5625
0.5225
0.4825
12.70
14.50
5/8
14
0.0457
0.6250
0.5793
0.5336
14.00
16.25
11/16
14
0.0457
0.6875
0.6418
0.5961
15.50
17.75
3/4
12
0.0534
0.7500
0.6966
0.6432
16.75
19.25
13/16
21.00
7/8
11
0.0582
0.8750
0.8168
0.7586
19.75
22.50
15/16
24.00
1
10
0.0640
1.0000
0.9360
0.8720
22.75
25.75
1 1/8
9
0.0711
1.1250
1.0539
0.9828
25.50
29.00
1 1/4
9
0.0711
1.2500
1.1789
1.1078
28.50
32.00
1 3/8
8
0.0800
1.3750
1.2950
1.2150
31.50
35.50
1 1/2
8
0.0800
1.5000
1.4200
1.3400
34.50
38.50
1 5/8
41.50
1 3/4
7
0.0915
1.7500
1.6585
1.5670
41.00
45.00
1 7/8
48.00
2
7
0.0915
2.0000
1.9085
1.8170
47.00
51.00
2 1/4
6
0.1067
2.2500
2.1433
2.0366
53.00
58.00
2 1/2
6
0.1067
2.5000
2.3933
2.2866
58.00
64.00
2 3/4
6
0.1067
2.7500
2.6433
2.5366
64.00
70.00
3
5
0.1280
3.0000
2.8719
2.7439
71.00
77.00