This specification covers welded and seamless carbon steel and austenitic stainless steel pipe nipples. The mechanical requirements stated that, pipe nipples shall be made from new, hydrostatic tested or NDE-tested pipe, pipe and nipples shall be threaded on both ends with NPT taper pipe threads. The standard and special lengths and sizes of nipples are presented. Galvanized nipples ordered under this specification shall be made from pipe coated on the inside and outside by the hot dip process. Samples of nipples sufficient to determine their conformance with the requirements of this specification shall be taken at random for each lot of nipples of the same pipe size, length, and material, also, samples shall be inspected to determine their conformance with the dimensional requirements, including thread dimensions.

1.1 This specification covers the requirements for welded and seamless carbon steel pipe nipples, black and zinc-coated (hot-dip galvanized), and welded and seamless austenitic stainless steel pipe nipples in standard steel pipe sizes from ¹/₈ to 12 in. inclusive, in standard or special lengths.

1.1.1 Welded Carbon Steel—Pipe nipples ordered under these requirements are intended for general uses, as described by Specification A53/A53M or for low-temperature service as described by Specification A333/A333M.

1.1.2 Seamless Carbon Steel—Pipe nipples ordered under these requirements are intended for general and special uses, as described by the applicable Specifications A53/A53M and A106/A106M or for low temperature service as described by Specification A333/A333M (see 4.1.1).

1.1.3 Austenitic Stainless Steel—Pipe nipples ordered under these requirements are intended for high-temperature and general corrosion service, as described by Specification A312/A312M (see 4.1.2).

1.1.4 The text for this specification contains notes or footnotes, or both, that provide explanatory material. Such notes and footnotes, excluding those in tables, do not contain any mandatory language.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.