Approximate Threads Per Inch	PITCH	Approximate Threads Per MM
338 1/2	0.075	133.33
317 1/2	0.080	125.00
282 1/4	0.090	111.11
254	0.100	100.00
203 1/2	0.125	80.00
169 1/4	0.150	66.67
145 1/4	0.175	57.14
127	0.200	50.00
101 1/2	0.250	40.00
84 3/4	0.300	33.33
72 1/2	0.350	28.57
63 1/2	0.400	25.00
56 1/2	0.450	22.22
50 3/4	0.500	20.00
42 1/4	0.600	16.67
36 1/4	0.700	14.29
33 3/4	0.750	13.33
31 3/4	0.800	12.50
28 1/4	0.900	11.11
25 1/2	1.000	10.00
20 1/4	1.250	8.00
17	1.500	6.67
14 1/2	1.750	5.71
12 3/4	2.000	5.00
10 1/4	2.500	4.00
8 1/2	3.000	3.33
7 1/4	3.500	2.86
6 1/4	4.000	2.50
5 3/4	4.500	2.22
5	5.000	2.00
4 1/2	5.500	1.82
4 1/4	6.000	1.67