Related Resources: hardware
Internal ACME Thread General Purpose Size Chart
ANSI Hardware Engineering Data
External ACME Thread General Purpose Size Table Chart
The following table defines recommended industry standard sizes for Internal ACME General Purpose Threads per American National Standard ASME/ANSI B1.5. All dimensional data is given in inches.
Designation |
Size Decimal |
TPI |
Tol. Class |
Minor Dia. |
Major Dia. |
||
Min. |
Max. |
Min. |
Max. |
||||
1/4-16 ACME |
0.25 |
16 |
2G |
0.1875 |
0.1925 |
0.2600 |
0.2700 |
1/4-16 ACME |
0.25 |
16 |
3G |
0.1875 |
0.1925 |
0.2600 |
0.2700 |
1/4-16 ACME |
0.25 |
16 |
4G |
0.1875 |
0.1925 |
0.2600 |
0.2700 |
1/4-16 ACME |
0.25 |
16 |
5G |
0.1875 |
0.1925 |
0.2600 |
0.2700 |
5/16-14 ACME |
0.3125 |
14 |
2G |
0.2411 |
0.2461 |
0.3225 |
0.3325 |
5/16-14 ACME |
0.3125 |
14 |
3G |
0.2411 |
0.2461 |
0.3225 |
0.3325 |
5/16-14 ACME |
0.3125 |
14 |
4G |
0.2411 |
0.2461 |
0.3225 |
0.3325 |
5/16-14 ACME |
0.3125 |
14 |
5G |
0.2411 |
0.2461 |
0.3225 |
0.3325 |
3/8-12 ACME |
0.375 |
12 |
2G |
0.2917 |
0.2967 |
0.3850 |
0.3950 |
3/8-12 ACME |
0.375 |
12 |
3G |
0.2917 |
0.2967 |
0.3850 |
0.3950 |
3/8-12 ACME |
0.375 |
12 |
4G |
0.2917 |
0.2967 |
0.3850 |
0.3950 |
3/8-12 ACME |
0.375 |
12 |
5G |
0.2917 |
0.2967 |
0.3850 |
0.3950 |
7/16-12 ACME |
0.4375 |
12 |
2G |
0.3542 |
0.3592 |
0.4475 |
0.4575 |
7/16-12 ACME |
0.4375 |
12 |
3G |
0.3542 |
0.3592 |
0.4475 |
0.4575 |
7/16-12 ACME |
0.4375 |
12 |
4G |
0.3542 |
0.3592 |
0.4475 |
0.4575 |
7/16-12 ACME |
0.4375 |
12 |
5G |
0.3542 |
0.3592 |
0.4475 |
0.4575 |
1/2-10 ACME |
0.5 |
10 |
2G |
0.4000 |
0.4050 |
0.52 |
0.5400 |
1/2-10 ACME |
0.5 |
10 |
3G |
0.4000 |
0.4050 |
0.52 |
0.5400 |
1/2-10 ACME |
0.5 |
10 |
4G |
0.4000 |
0.4050 |
0.52 |
0.5400 |
1/2-10 ACME |
0.5 |
10 |
5G |
0.4000 |
0.4050 |
0.52 |
0.5400 |
5/8-8 ACME |
0.625 |
8 |
2G |
0.5000 |
0.5062 |
0.645 |
0.6650 |
5/8-8 ACME |
0.625 |
8 |
3G |
0.5000 |
0.5062 |
0.645 |
0.6650 |
5/8-8 ACME |
0.625 |
8 |
4G |
0.5000 |
0.5062 |
0.645 |
0.6650 |
5/8-8 ACME |
0.625 |
8 |
5G |
0.5000 |
0.5062 |
0.645 |
0.6650 |
3/4-6 ACME |
0.75 |
6 |
2G |
0.5833 |
0.5916 |
0.77 |
0.7900 |
3/4-6 ACME |
0.75 |
6 |
3G |
0.5833 |
0.5916 |
0.77 |
0.7900 |
3/4-6 ACME |
0.75 |
6 |
4G |
0.5833 |
0.5916 |
0.77 |
0.7900 |
3/4-6 ACME |
0.75 |
6 |
5G |
0.5833 |
0.5916 |
0.77 |
0.7900 |
7/8-6 ACME |
0.875 |
6 |
2G |
0.7083 |
0.7166 |
0.895 |
0.9150 |
7/8-6 ACME |
0.875 |
6 |
3G |
0.7083 |
0.7166 |
0.895 |
0.9150 |
7/8-6 ACME |
0.875 |
6 |
4G |
0.7083 |
0.7166 |
0.895 |
0.9150 |
7/8-6 ACME |
0.875 |
6 |
5G |
0.7083 |
0.7166 |
0.895 |
0.9150 |
1-5 ACME |
1 |
5 |
2G |
0.8000 |
0.8100 |
1.02 |
1.0400 |
1-5 ACME |
1 |
5 |
3G |
0.8000 |
0.8100 |
1.02 |
1.0400 |
1-5 ACME |
1 |
5 |
4G |
0.8000 |
0.8100 |
1.02 |
1.0400 |
1-5 ACME |
1 |
5 |
5G |
0.8000 |
0.8100 |
1.02 |
1.0400 |
1 1/8-5 ACME |
1.125 |
5 |
2G |
0.9250 |
0.9350 |
1.145 |
1.165 |
1 1/8-5 ACME |
1.125 |
5 |
3G |
0.9250 |
0.9350 |
1.145 |
1.165 |
1 1/8-5 ACME |
1.125 |
5 |
4G |
0.9250 |
0.9350 |
1.145 |
1.165 |
1 1/8-5 ACME |
1.125 |
5 |
5G |
0.9250 |
0.9350 |
1.145 |
1.165 |
1 1/4-5 ACME |
1.25 |
5 |
2G |
1.0500 |
1.0600 |
1.27 |
1.29 |
1 1/4-5 ACME |
1.25 |
5 |
3G |
1.0500 |
1.0600 |
1.27 |
1.29 |
1 1/4-5 ACME |
1.25 |
5 |
4G |
1.0500 |
1.0600 |
1.27 |
1.29 |
1 1/4-5 ACME |
1.25 |
4 |
5G |
1.0500 |
1.0600 |
1.27 |
1.29 |
1 3/8-4 ACME |
1.375 |
4 |
2G |
1.1250 |
1.1375 |
1.395 |
1.415 |
1 3/8-4 ACME |
1.375 |
4 |
3G |
1.1250 |
1.1375 |
1.395 |
1.415 |
1 3/8-4 ACME |
1.375 |
4 |
4G |
1.1250 |
1.1375 |
1.395 |
1.415 |
1 3/8-4 ACME |
1.375 |
4 |
5G |
1.1250 |
1.1375 |
1.395 |
1.415 |
1 1/2-4 ACME |
1.5 |
4 |
2G |
1.2500 |
1.2625 |
1.52 |
1.54 |
1 1/2-4 ACME |
1.5 |
4 |
3G |
1.2500 |
1.2625 |
1.52 |
1.54 |
1 1/2-4 ACME |
1.5 |
4 |
4G |
1.2500 |
1.2625 |
1.52 |
1.54 |
1 1/2-4 ACME |
1.5 |
4 |
5G |
1.2500 |
1.2625 |
1.52 |
1.54 |
1 3/4-4 ACME |
1.75 |
4 |
2G |
1.5000 |
1.5125 |
1.77 |
1.79 |
1 3/4-4 ACME |
1.75 |
4 |
3G |
1.5000 |
1.5125 |
1.77 |
1.79 |
1 3/4-4 ACME |
1.75 |
4 |
4G |
1.5000 |
1.5125 |
1.77 |
1.79 |
1 3/4-4 ACME |
1.75 |
4 |
5G |
1.5000 |
1.5125 |
1.77 |
1.79 |
2-4 ACME |
2 |
4 |
2G |
1.7500 |
1.7625 |
2.02 |
2.04 |
2-4 ACME |
2 |
4 |
3G |
1.7500 |
1.7625 |
2.02 |
2.04 |
2-4 ACME |
2 |
4 |
4G |
1.7500 |
1.7625 |
2.02 |
2.04 |
2-4 ACME |
2 |
4 |
5G |
1.7500 |
1.7625 |
2.02 |
2.04 |
2 1/4-3 ACME |
2.25 |
3 |
2G |
1.9167 |
1.9334 |
2.27 |
2.29 |
2 1/4-3 ACME |
2.25 |
3 |
3G |
1.9167 |
1.9334 |
2.27 |
2.29 |
2 1/4-3 ACME |
2.25 |
3 |
4G |
1.9167 |
1.9334 |
2.27 |
2.29 |
2 1/4-3 ACME |
2.25 |
3 |
5G |
1.9167 |
1.9334 |
2.27 |
2.29 |
2 1/2-3 ACME |
2.5 |
3 |
2G |
2.1667 |
2.1834 |
2.52 |
2.54 |
2 1/2-3 ACME |
2.5 |
3 |
3G |
2.1667 |
2.1834 |
2.52 |
2.54 |
2 1/2-3 ACME |
2.5 |
3 |
4G |
2.1667 |
2.1834 |
2.52 |
2.54 |
2 1/2-3 ACME |
2.5 |
3 |
5G |
2.1667 |
2.1834 |
2.52 |
2.54 |
2 3/4-3 ACME |
2.75 |
3 |
2G |
2.4169 |
2.4334 |
2.77 |
2.79 |
2 3/4-3 ACME |
2.75 |
3 |
3G |
2.4169 |
2.4334 |
2.77 |
2.79 |
2 3/4-3 ACME |
2.75 |
3 |
4G |
2.4169 |
2.4334 |
2.77 |
2.79 |
2 3/4-3 ACME |
2.75 |
3 |
5G |
2.4169 |
2.4334 |
2.77 |
2.79 |
3-2 ACME |
3 |
2 |
2G |
2.5000 |
2.5250 |
3.02 |
3.04 |
3-2 ACME |
3 |
2 |
3G |
2.5000 |
2.5250 |
3.02 |
3.04 |
3-2 ACME |
3 |
2 |
4G |
2.5000 |
2.5250 |
3.02 |
3.04 |
3-2 ACME |
3 |
2 |
5G |
2.5000 |
2.5250 |
3.02 |
3.04 |
3 1/2-2 ACME |
3.5 |
2 |
2G |
3.0000 |
3.0250 |
3.52 |
3.54 |
3 1/2-2 ACME |
3.5 |
2 |
3G |
3.0000 |
3.0250 |
3.52 |
3.54 |
3 1/2-2 ACME |
3.5 |
2 |
4G |
3.0000 |
3.0250 |
3.52 |
3.54 |
3 1/2-2 ACME |
3.5 |
2 |
5G |
3.0000 |
3.0250 |
3.52 |
3.54 |
4-2 ACME |
4 |
2 |
2G |
3.5000 |
3.5250 |
4.02 |
4.04 |
4-2 ACME |
4 |
2 |
3G |
3.5000 |
3.5250 |
4.02 |
4.04 |
4-2 ACME |
4 |
2 |
4G |
3.5000 |
3.5250 |
4.02 |
4.04 |
4-2 ACME |
4 |
2 |
5G |
3.5000 |
3.5250 |
4.02 |
4.04 |
4 1/2-2 ACME |
4.5 |
2 |
2G |
4.0000 |
4.0250 |
4.52 |
4.54 |
4 1/2-2 ACME |
4.5 |
2 |
3G |
4.0000 |
4.0250 |
4.52 |
4.54 |
4 1/2-2 ACME |
4.5 |
2 |
4G |
4.0000 |
4.0250 |
4.52 |
4.54 |
4 1/2-2 ACME |
4.5 |
2 |
5G |
4.0000 |
4.0250 |
4.52 |
4.54 |
5-2 ACME |
5 |
2 |
2G |
4.5000 |
4.5250 |
5.02 |
5.04 |
5-2 ACME |
5 |
2 |
3G |
4.5000 |
4.5250 |
5.02 |
5.04 |
5-2 ACME |
5 |
2 |
4G |
4.5000 |
4.5250 |
5.02 |
5.04 |
5-2 ACME |
5 |
2 |
5G |
4.5000 |
4.5250 |
5.02 |
5.04 |
Designation |
TPI |
Tol. Class |
Pitch Dia. |
Tap Drill |
|
Min. |
Max. |
||||
1/4-16 ACME |
16 |
2G |
0.2188 |
0.2293 |
0.1875 |
1/4-16 ACME |
16 |
3G |
0.2188 |
0.2237 |
0.1875 |
1/4-16 ACME |
16 |
4G |
0.2188 |
0.2223 |
0.1875 |
1/4-16 ACME |
16 |
5G |
0.2188 |
0.2216 |
0.1875 |
5/16-14 ACME |
14 |
2G |
0.2768 |
0.2882 |
0.2411 |
5/16-14 ACME |
14 |
3G |
0.2768 |
0.2821 |
0.2411 |
5/16-14 ACME |
14 |
4G |
0.2768 |
0.2806 |
0.2411 |
5/16-14 ACME |
14 |
5G |
0.2768 |
0.2798 |
0.2411 |
3/8-12 ACME |
12 |
2G |
0.3333 |
0.3456 |
0.2917 |
3/8-12 ACME |
12 |
3G |
0.3333 |
0.3391 |
0.2917 |
3/8-12 ACME |
12 |
4G |
0.3333 |
0.3374 |
0.2917 |
3/8-12 ACME |
12 |
5G |
0.3333 |
0.3366 |
0.2917 |
7/16-12 ACME |
12 |
2G |
0.3958 |
0.4084 |
0.3542 |
7/16-12 ACME |
12 |
3G |
0.3958 |
0.4017 |
0.3542 |
7/16-12 ACME |
12 |
4G |
0.3958 |
0.4000 |
0.3542 |
7/16-12 ACME |
12 |
5G |
0.3958 |
0.3992 |
0.3542 |
1/2-10 ACME |
10 |
2G |
0.4500 |
0.4637 |
0.4000 |
1/2-10 ACME |
10 |
3G |
0.4500 |
0.4564 |
0.4000 |
1/2-10 ACME |
10 |
4G |
0.4500 |
0.4546 |
0.4000 |
1/2-10 ACME |
10 |
5G |
0.4500 |
0.4537 |
0.4000 |
5/8-8 ACME |
8 |
2G |
0.5625 |
0.5779 |
0.5000 |
5/8-8 ACME |
8 |