Description

This specification covers dimensional requirements on threads and thread gages and stipulations on gaging practice, gage specifications and certification as well as the instruments and methods for the inspection of threads for line pipe, round-thread casing and tubing, buttress casing and extreme-line casing joints. It is applicable when so stipulated in the API standard governing the product. The inspection procedures for measurements of taper, lead, height, and angle of thread are applicable only to threads having 11 '¹/₂ or less turns per inch.

Thread inspection applies at the point of manufacture prior to shipment, to inspection at any intermediate point, to inspection subsequent to delivery at destination, and to inspection by inspectors representing the purchaser or the manufacturer. The manufacturer may, at his option, use other instruments or methods to control manufacturing operations; but acceptance and rejection of the product shall be governed solely by the results of inspection made in accordance with the requirements of this specification.