Specifications of International Thread Standards

16-UN - Unified Extra Fine Thread, which is used for special purposes.
The flank angle is 60°.

Nominal
Diameter
Major
Diameter
Inch
Major
Diameter
mm
Tapping
Drill Size
mm
TPIPitch
mm
7/16" - 16-UN0.437511.1129.576161.587
1/2" - 16-UN0.500012.70011.200161.587
9/16" - 16-UN0.562514.28812.800161.587
5/8" - 16-UN0.625015.87514.400161.587
11/16" - 16-UN0.687517.46216.000161.587
13/16" - 16-UN0.812520.63719.100161.587
7/8" - 16-UN0.875022.22520.700161.587
15/16" - 16-UN0.937523.81322.300161.587
1" - 16-UN1.000025.40023.900161.587
1 1/16" - 16-UN1.062526.98725.500161.587
1 1/8" - 16-UN1.125028.57527.100161.587
1 3/16" - 16-UN1.187530.16228.700161.587
1 1/4" - 16-UN1.250031.75030.300161.587
1 5/16" - 16-UN1.312533.33731.750161.587
1 3/8" - 16-UN1.375034.92533.400161.587
1 7/16" - 16-UN1.437536.51235.000161.587
1 1/2" - 16-UN1.500038.10036.600161.587
1 9/16" - 16-UN1.562539.68838.200161.587
1 5/8" - 16-UN1.625041.27539.800161.587
1 11/16" - 16-UN1.687542.86241.350161.587
1 3/4" - 16-UN1.750044.45043.000161.587
1 13/16" - 16-UN1.812546.03744.500161.587
1 7/8" - 16-UN1.875047.62546.100161.587
1 15/16" - 16-UN1.937549.21247.700161.587
2" - 16-UN2.000050.80049.300161.587
2 1/8" - 16-UN2.125053.97552.600161.587
2 1/4" - 16-UN2.250057.15055.650161.587
2 3/8" - 16-UN2.375060.32558.850161.587
2 1/2" - 16-UN2.500063.50062.000161.587
2 5/8" - 16-UN2.625066.67565.150161.587
2 3/4" - 16-UN2.750069.85068.350161.587
2 7/8" - 16-UN2.875073.02571.500161.587
3" - 16-UN3.000076.20074.700161.587
3 1/8" - 16-UN3.125079.37577.850161.587
3 1/4" - 16-UN3.250082.55081.000161.587
3 3/8" - 16-UN3.375085.72584.200161.587
3 1/2" - 16-UN3.500088.90087.400161.587
3 5/8" - 16-UN3.625092.07590.550161.587
3 3/4" - 16-UN3.750095.25093.750161.587
3 7/8" - 16-UN3.875098.42596.900161.587
4" - 16-UN4.0000101.600100.100161.587
4 1/8" - 16-UN4.1250104.775103.300161.587
4 1/4" - 16-UN4.2500107.950106.450161.587
4 3/8" - 16-UN4.3750111.125109.600161.587
4 1/2" - 16-UN4.5000114.300112.800161.587
4 5/8" - 16-UN4.6250117.475116.000161.587
4 3/4" - 16-UN4.7500120.650119.150161.587
4 7/8" - 16-UN4.8750123.825122.300161.587
5" - 16-UN5.0000127.000125.500161.587
5 1/4" - 16-UN5.2500133.350131.850161.587
5 1/2" - 16-UN5.5000139.700138.200161.587
5 5/8" - 16-UN5.6250142.875141.350161.587
5 7/8" - 16-UN5.8750149.225147.750161.587
6" - 16-UN6.0000152.400150.900161.587
16-UN Thread