1.Experienced Manufacturer, 2.Reliable quality 3.Reasonable price 1. We provide standard & non standard pipe thread gauges.2. Conform: API 7 , API3.Gauge Code:NC-10,12,13,16,23,26,31,35,38,40,46,50,56,1,70,77REG- 2 3/8, 2 7/8, 3 1/2, 4 1/2, 5 1/2, 6 5/8, 7 5/8, 8 5/8FH - 2 7/8, 3 1/2, 4 1/2, 5 1/2, 6 5/8 Ring Thread Gauges