ASTM A335 steel pipe.

1. Scope
1.1 This specification covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high-temperature service. Pipe ordered to this specification shall be suitable for bending, flanging
(vanstoning), and similar forming operations, and for fusion welding. Selection will depend upon
design, service conditions, mechanical properties, and high-temperature characteristics.
1.2 Several grades of ferritic steels (see Note 1) are covered. Their compositions are given in
Table 1.
Note 1Ferritic steels in this specification are defined as low- and intermediate-alloy steels containing up to and including 10 % chromium.
1.3 Supplementary requirements (S1 to S7) of an optional nature are provided. These
supplementary requirements call for additional tests to be made, and when desired, shall be
so stated in the order together with the number of such tests required.
1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units
are shown in brackets. The values stated in each system are not exact equivalents; therefore,
each system must be used independently of the other. Combining values from the two systems may result in nonconformance
with the specification. The inchpound units shall apply unless the "M" designation of this specification is specified in the order.
Note 2The dimensionless designator NPS (nominal pipe size) has been substituted in this
standard for such traditional terms as "nominal diameter," "size," and "nominal size."