PMC Lone Star maintains the most complete source of Master Gages outside of N.I.S.T.  All gages are made of tool steel hardened to Rockwell C 60-62 and are cryogenically frozen to insure their stability.  Each gage is put through a series of in-process and final inspections with tolerances to ±0.0002 of an inch (±5 µm).  We then qualify each gage using a certified master gage, and provide a calibration report detailing the measured dimensions and the serial number of the master gage used for the inspection. The quality and reliability of our gages have made them the overwhelming choice of coupling shops, pipe and tube mills around the world. PMC Lone Star is ready with a trained staff of gage experts to help you accomplish all of your gaging needs, whether they are API sanctioned threads or premium proprietary connections.