We supply complete line of API 5B & 7-2 gauges (working & master). The prominent advantages of our gauges are: excellent accuracy and durability. In the field of thread gauge manufacturing, we have been promoting the development of thread gauges and improving our product quality and reliability continually. Facts have proven that our master & working gauges strictly conforms to specifications established by API. We strongly believe that our traceable measuring system established through API-certified master gauges and high-precision measuring equipments will fully satisfy your requirements.

All our gauges come with third-party calibration certificates that are traceable to NIST and valid for API audit. We make sure every set of gauges we send out to you strictly conforms to API specifications.

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.