Dial Indicators, Micrometers, Calipers manufacturer / supplier in China, offering API Spec 5b 3" Lp Line Pipe Thread Gages with 60-63HRC for Oilfield Thread Inspection, API 5b Oilfield Line Pipe Thread Gauge 3 Inch Lp Calibrated Inspection Gauge for The Petroleum and Natural Gas Industry, API Spec 5b 2"Lp Line Pipe Thread Gauge for Oilfield Thread Inspection and so on.