UNC

UNC - Unified Coarse Thread

UNC threads ANSI B1.1
Nominal Diameter
(in)
Threads per inchMajor Diameter
(in)
Major Diameter
(mm)
Tapping Drill Size
(mm)
Pitch
(mm)
1640.0731.8541.50.397
2560.0862.1841.80.453
3480.0992.5152.10.529
4400.1122.8452.350.635
5400.1253.1752.650.635
6320.1383.5052.850.794
8320.1644.1663.50.794
10240.194.82641.058
12240.2165.4864.651.058
1/4"200.256.355.351.27
5/16"180.3137.9386.81.411
3/8"160.3759.5258.251.587
7/16"140.43811.1129.651.814
1/2"130.512.711.151.954
9/16"120.56314.28812.62.117
5/8"110.62515.87514.052.309
3/4"100.7519.05172.54
7/8"90.87522.225202.822
1"8125.422.853.175
1 1/8"71.12528.57525.653.628
1 1/4"71.2531.7528.853.628
1 3/8"61.37543.92531.554.233
1 1/2"61.538.134.74.233
1 3/4"51.7544.4540.45.08
2"4.5250.846.35.644
2 1/4"4.52.2557.1552.655.644
2 1/2"42.563.558.56.35
2 3/4"42.7569.8564.756.35
3"4376.271.16.35
3 1/4"43.2582.5577.456.35
3 1/2"43.588.983.86.35
3 3/4"43.7595.2590.156.35
4"44101.696.56.35