Specifications of International Thread Standards

British Standard Pipe Parallel Thread, with sealant compound,(parallel, cylindrical), external = G.
The flank angle is 55°.

Nominal
Diameter
Major
Diameter
Inch
Major
Diameter
mm
Minor Diamter
Nut
mm
Tapping
Drill Size
mm
TPIPitch
mm
G 1/16"0.0637.7226.8436.561280.907
G 1/8"0.1259.7288.8488.565280.907
G 1/4"0.25013.15711.89011.445191.337
G 3/8"0.37516.66215.39514.950191.337
G 1/2"0.50020.95519.17218.633141.814
G 5/8"0.62522.91121.12820.587141.814
G 3/4"0.75026.44124.65824.120141.814
G 7/8"0.87530.20128.41827.877141.814
G 1"1.00033.24930.93130.292112.309
G 1 1/8"1.12537.89735.57934.939112.309
G 1 1/4"1.25041.91039.59238.953112.309
G 1 3/8"1.37544.32342.00541.365112.309
G 1 1/2"1.50047.80345.48544.846112.309
G 1 5/8"1.62552.88350.56649.926112.309
G 1 3/4"1.75053.74651.42850.788112.309
G 1 7/8"1.87556.99854.68154.041112.309
G 2"2.00059.61457.29656.657112.309
G 2 1/4"2.25065.71062.75263.392112.309
G 2 1/2"2.50075.18473.39172.227112.309
G 2 3/4"2.75081.53478.57679.216112.309
G 3"3.00087.88486.28984.927112.309
G 3 1/2"3.500100.33097.37298.012112.309
G 4"4.000113.030111.733110.073112.309
G 4 1/2"4.500125.730122.772123.412112.309
G 5"5.000138.430137.332135.473112.309
G 5 1/2"5.500151.130148.172148.812112.309
G 6"6.000163.830162.732160.873112.309
Whitworth Pipe Thread