American Petroleum Institute

Specification for Threading, Gaging, and Thread Inspection of Casing, Tubing, and Line Pipe Threads - THIRTEENTH EDITION; SUPP 1: July 1, 1990
 N STD 5B

Annotation

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? or less turns per inch. All thread dimensions shown without tolerances are related to the basis for joint design and are not subject to measurement to determine acceptance or rejection of product.

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.

Although this specification contains complete dimensional information for threading and gaging buttress and extreme-line casing joints, considerable skill and know-how is required for the tooling for, and machining of, these joints. Therefore, any manufacturer who desires to produce these joints is advised to consult with manufacturers who have produced these joints before attempting their manufacture.

This specification is under the jurisdiction of the API Committee on Standardization of Tubular Goods.