| Thread | T.P.I UNC | T.P.I UNF | a | h | Drive | L* |
| 0 |
* |
80 |
0.112-0.096 |
0.035 |
#0 |
1/8 |
| 1 |
64 |
72 |
0.137-0.120 |
0.043 |
#0 |
1/8 |
| 2 |
56 |
64 |
0.162-0.144 |
0.051 |
#1 |
1/8 |
| 3 |
48 |
56 |
0.187-0.167 |
0.059 |
#1 |
1/8 |
| 4 |
40 |
48 |
0.212-0.191 |
0.067 |
#1 |
3/16 |
| 5 |
40 |
44 |
0.237-0.215 |
0.075 |
#2 |
3/16 |
| 6 |
32 |
40 |
0.262-0.238 |
0.083 |
#2 |
3/16 |
| 8 |
32 |
36 |
0.312-0.285 |
0.100 |
#2 |
1/4 |
| 10 |
24 |
32 |
0.362-0.333 |
0.116 |
#2 |
5/16 |
| 12 |
24 |
28 |
0.412-0.380 |
0.132 |
#3 |
3/8 |
| 1/4 |
20 |
28 |
0.477-0.442 |
0.153 |
#3 |
7/16 |
| 5/16 |
18 |
24 |
0.597-0.556 |
0.191 |
#4 |
1/2 |
| 3/8 |
16 |
24 |
0.717-0.670 |
0.230 |
#4 |
9/16 |
| * Heads will be undercut on lengths less than L |
