Thread Identification Chart (British) - Fuller Fasteners
https://fullerfasteners.com › tech › th...Basic Major Diameter, Nominal Diameter. (mm). Threads Per Inch. Inch, mm, BA, BSW, BSF, BSP, BSPT .0118, 0.30 .0118, 0.30 .0138, 0.35 .0146, 0.37, 22, 254.