GB/T 22091.1-2008 55°密封管螺纹量规 第1部分:用于检验圆柱内螺纹与圆锥外螺纹 Gauges for pipe threads with 55 degree thread angle where pressure-tight joints are made on the threads - Part 1:Verification of parallel internal and taper external threads
Gauges for pipe threads with 55 degree thread angle where pressure-tight joints are made on the threads - Part 1:Verification of parallel internal and taper external threads