This standard is issued under the fixed designation A 453/A 453M: the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last repproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval

1. Scope
1.1 This specificationcovers four grades of bolting mate-rials with nine classes of yield strength ranging from 50 to 120 ksi [345 to 827 MPa] for use in high-temperature service such as fasteners for pressure vessel and valve flanges. The material requires special processing and is not intended for general purpose applications. The term "bolting material,"asused in this specification, covers rolled, forged, or hot-extruded bars; bolts, nuts. screws. washers, studs.and stud bolts. Headed bolts and rolled threads may be supplied.

Note 1_ other bolting materials are covered by specification A 193/A 193M and specification A 437/A 437M.

1.2 Supplementary Requirement S1 of an optional nature is provided. This shall apply only when specified by the purchaser in th order.
1.3 This specification is expressed in both inch-pound units and in SI units. However, unless the order specifies the applicabel "M" specification designation (SI units), the material shall be furnished to inch-pound units/
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.