Specifies thread profile and provides information on designation, thread classes, deviations and gauging. Limits of size for both coarse pitch series (BSW) and fine pitch series (BSF), together with associated tolerances, are given. It also covers screw gauges and associated setting plugs, and plain plug and calliper gauges, and includes information on types of gauges, gauge deviations and tolerances, materials and hardness, general gauge design requirements, marking, and general notes on the inspection of screw threads. Appendices give information on special threads, pitch diameter of pitch and flank angle errors, and notes on screw thread verification.