1.1 This specification covers five grades of electric-fusion (arc)-welded straight-seam or spiral-seam steel pipe in NPS 4 to 92 (Note 1) inclusive with nominal (average) wall thicknesses up to 1.0 in. (25.4 mm), inclusive. Pipe having other dimensions (Note 2) may be furnished provided such pipe complies with all other requirements of this specification. The grades of steel are pipe mill grades having mechanical properties which differ from standard plate grades. The pipe is intended for conveying liquid, gas, or vapor.

Note 1-The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as "nominal diameter," "size," and "nominal size."

Note 2-A comprehensive listing of standardized pipe dimensions is contained in ANSI B36.10.

Note 3-The suitability of pipe for various purposes is somewhat dependent on its dimensions, properties, and conditions of service. For example, for high-temperature service see applicable codes and Specification A 691.

1.2 The values stated in inch-pound units are to be regarded as the standard.