Specifies requirements for gauges for single start parallel general purpose metric screw threads manufactured to either AS 1721 or AS 1275. It covers types of gauges, inspection of screw threads, design features of screw gauges, material and hardness requirements, and limits and tolerances of gauging elements, and is technically identical with ISO 1502, ISO General Purpose Metric Screw Threads - Gauging. Appendices give notes on the function, use and checking of gauges, the bases for the gauge deviations and tolerances, and detailed examples of deriving specific gauge limits.