The American Petroleum Institute (A.P.I.) established a tightly controlled gaging program to insure that the A.P.I. thread form specifications are met in the manufacturing of oil field equipment, tools and pipe. A.P.I. requires that those manufacturers using the A.P.I. monogram inspect these components with working gages set to A.P.I. master gages. HEMCO is certified by the Institute to use the A.P.I. monogram on all Spec 5B, 7 and 11B Master Gage we manufacture.
NOTE: Only API reference Master Gage may be marked with the API monogram