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British Standard Cycle (B.S.C.)
Thread Form
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- p = Pitch = 1/TPI
- h = Basic Depth of Thread = 0.5327p
- r = Basic Radius = 0.166p
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Thread Tables
Nominal Size |
T.P.I. |
Basic Thread Depth |
Basic Major Diameter |
Basic Effective Diameter |
Basic Minor Diameter |
Tapping Drill |
Clearing Drill |
(inch) |
(n/a) |
(inch) |
(inch) |
(inch) |
(inch) |
(mm) |
(mm) |
1/8 |
40 |
0.0133 |
0.125 |
0.1117 |
0.0984 |
2.5 |
3.3 |
5/32 |
32 |
0.0166 |
0.1563 |
0.1397 |
0.1231 |
3.25 |
4.1 |
3/16 |
32 |
0.0166 |
0.1875 |
0.17085 |
0.1542 |
3.97 |
4.9 |
1/4 |
26 |
0.0205 |
0.25 |
0.22955 |
0.2091 |
5.56 |
6.5 |
9/32 |
26 |
0.0205 |
0.281 |
0.26065 |
0.2403 |
6.2 |
7.3 |
5/16 |
26 |
0.0205 |
0.3125 |
0.292 |
0.2715 |
7 |
8.1 |
3/8 |
26 |
0.0205 |
0.375 |
0.3545 |
0.334 |
8.65 |
9.7 |
7/16 |
26 |
0.0205 |
0.4375 |
0.417 |
0.3965 |
10.1 |
11.3 |
1/2 |
26 |
0.0205 |
0.5 |
0.4795 |
0.459 |
11.7 |
13 |
9/16 |
26 |
0.0205 |
0.5625 |
0.542 |
0.5215 |
13.1 |
14.5 |
5/8 |
26 |
0.0205 |
0.625 |
0.6045 |
0.584 |
15 |
16.25 |
11/16 |
26 |
0.0205 |
0.6875 |
0.667 |
0.6465 |
16.5 |
17.75 |
1 |
26 |
0.0205 |
1 |
0.9795 |
0.959 |
24.61 |
25.75 |
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