Material: The material we use for our API thread gages (thread gauges) is bearing steel that is hardened to Rockwell C60-63 and is put through series of special treatments, such as aging treatment, heat treatment and freezing treatment, to ensure to provide high precision and rigid stability during long period of usage.
Inspection: Each set of our API thread gages (thread gauges) undergoes 3 phases of strict inspections before they are sent out to our customers:
1, In-process inspection: We will do inspection at every procedure of the manufacturing process.
2,Final inspection: After the gages are finished, we will inspect every thread element of each piece of gauge and calibrate them with certified master gauges.
3,Third-party calibration: Before we deliver gages to you, we will send them to Baoji Baoshi Petroleum Thread Gauges Inspection Center for third-party calibration. The Center will issue a calibration certificate detailing the measured standoff values and the serial number of the master gages. The calibration certificate is traceable to NIST and valid for API audit.