BSB British Standard Brass

BSB British Standard Brass Thread. Used brass tubing. BSB has a 26 TPI pitch through the whole range.
The flank angle is 55°.

Nominal
Diameter
Diameter
Inch
Diameter
mm
Tapping Drill Size
mm
TPI Pitch
mm
BSB 1/8" 0.125 3.175 1.923 26 0.977
BSB 1/4" 0.250 5.556 5.098 26 0.977
BSB 3/8" 0.375 9.525 8.273 26 0.977
BSB 1/2" 0.500 12.700 11.448 26 0.977
BSB 5/8" 0.625 15.875 14.369 26 0.977
BSB 3/4" 0.750 19.050 17.798 26 0.977
BSB 7/8" 0.875 22.225 20.973 26 0.977
BSB 1" 1.000 25.400 24.148 26 0.977
BSB 1 1/8" 1.500 28.575 27.323 26 0.977
BSB 1 1/4" 1.250 31.750 30.498 26 0.977
BSB 1 1/2" 1.500 38.100 36.848 26 0.977