American Petroleum Institute

SPECIFICATION FOR HIGH-STRENGTH CASING AND TUBING - Seventh Edition; Incorporating Supplement: April 1969
 N STD 5AX

Annotation

Coverage. This specification covers high-strength seamless steel casing and tubing. It includes casing and non-upset and external-upset tubing, in the sizes and wail thicknesses shown in the standard lists (Tables 1.1 and 1.2), and the dimensional tables (Tables 6.1 through 6.6). It also includes requirements for couplings and thread protectors.

Dimensional requirements on threads and thread gages, stipulations on gaging practice, gage specifications and certification, as well as instruments and methods for inspection of threads are given in API Std 5B and are applicable to products covered by this specification.

Although this specification, in conjunction with API Std 5B, permits manufacturers authorized to use the API monogram on round-thread casing to manufacture and apply the monogram to buttress and extreme-line casing, 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.

Policy. American Petroleum Institute (API) specifications are published as an aid to procurement of standardized equipment and materials. These specifications are not intended to inhibit purchasers and producers from purchasing or producing products made to specifications other than API, and nothing in any API specification is intended to in any way inhibit the purchase of products from companies not authorized to use the API monogram.*

Nothing contained in any API specification is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use in connection with any method, apparatus or product covered by letters patent, nor as insuring anyone against liability for infringement of letters patent.