Specifications of International Thread Standards

12-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
5/8" - 12-UN0.625015.87513.900122.117
11/16" - 12-UN0.687517.46215.500122.117
3/4" - 12-UN0.750019.05017.000122.117
13/16" - 12-UN0.812520.63718.600122.117
7/8" - 12-UN0.875022.22520.200122.117
15/16" - 12-UN0.937523.81321.800122.117
1 1/16" - 12-UN1.062526.98725.000122.117
1 3/16" - 12-UN1.187530.16228.200122.117
1 5/16" - 12-UN1.312533.33731.300122.117
1 7/16" - 12-UN1.437536.51234.500122.117
1 9/16" - 12-UN1.562539.68837.700122.117
1 5/8" - 12-UN1.625041.27539.300122.117
1 11/16" - 12-UN1.687542.86240.850122.117
1 3/4" - 12-UN1.750044.45042.400122.117
1 13/16" - 12-UN1.812546.03744.000122.117
1 7/8" - 12-UN1.875047.62545.600122.117
1 15/16" - 12-UN1.937549.21247.200122.117
2" - 12-UN2.000050.80048.800122.117
2 1/8" - 12-UN2.125053.97552.000122.117
2 1/4" - 12-UN2.250057.15055.100122.117
2 3/8" - 12-UN2.375060.32558.300122.117
2 1/2" - 12-UN2.500063.50061.500122.117
2 5/8" - 12-UN2.625066.67564.700122.117
2 3/4" - 12-UN2.750069.85067.800122.117
2 7/8" - 12-UN2.875073.02571.000122.117
3" - 12-UN3.000076.20074.200122.117
3 1/8" - 12-UN3.125079.37577.400122.117
3 1/4" - 12-UN3.250082.55080.500122.117
2 3/8" - 12-UN3.375085.72583.700122.117
3 1/2" - 12-UN3.500088.90086.900122.117
3 5/8" - 12-UN3.625092.07590.100122.117
3 3/4" - 12-UN3.750095.25093.250122.117
3 7/8" - 12-UN3.875098.42596.400122.117
4" - 12-UN4.0000101.60099.600122.117
4 1/8" - 12-UN4.1250104.775102.800122.117
4 1/4" - 12-UN4.2500107.950105.900122.117
4 3/8" - 12-UN4.3750111.125109.100122.117
4 1/2" - 12-UN4.5000114.300112.300122.117
4 5/8" - 12-UN4.6250117.475115.500122.117
4 3/4" - 12-UN4.7500120.650118.700122.117
4 7/8" - 12-UN4.8750123.825121.700122.117
5" - 12-UN5.0000127.000125.000122.117
5 1/8" - 12-UN5.1250130.175128.200122.117
5 1/4" - 12-UN5.2500133.350131.400122.117
5 3/8" - 12-UN5.3750136.525134.500122.117
5 1/2" - 12-UN5.5000139.700137.700122.117
5 5/8" - 12-UN5.6250142.875140.900122.117
5 3/4" - 12-UN5.7500146.050144.000122.117
6" - 12-UN6.0000152.400150.400122.117
12-UN Thread