This specification covers alloy steel and stainless steel bolting material for pressure vessels, valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications. Ferritic steels shall be properly heat treated as best suits the high temperature characteristics of each grade. Immediately after rolling or forging, the bolting material shall be allowed to cool to a temperature below the cooling transformation range. The chemical composition requirements for each alloy are presented in details. The steel shall not contain an unspecified element for ordered grade to the extent that the steel conforms to the requirements of another grade for which that element is a specified element. The tensile property and hardness property requirements are discussed, the tensile property requirement is highlighted by a full size fasteners, wedge tensile testing.
1.1 This specification covers alloy and stainlesssteel bolting for pressure vessels, valves, flanges, and fittingsfor high temperature or high pressure service, or other specialpurpose applications. See Specification A962/A962M for the definition of bolting. Bars and wire shallbe hot-wrought and may be further processed by centerless grindingor by cold drawing. Austenitic stainless steel may be carbidesolution treated or carbide solution treated and strain-hardened.When strain hardened austenitic steel is ordered, the purchasershould take special care to ensure that Appendix X1 is thoroughlyunderstood.
1.2 Several grades are covered, including ferriticsteels and austenitic stainless steels designated B5, B8, and soforth. Selection will depend upon design, service conditions,mechanical properties, and high temperature characteristics.
1.3 The following referenced general requirementsare indispensable for application of this specification:Specification A962/A962M.
Note1—The committee formulating this specification has included fifteensteel types that have been rather extensively used for the presentpurpose. Other compositions will be considered for inclusion by thecommittee from time to time as the need becomes apparent.
Note2—For grades of alloy-steel bolting suitable for use at the lowerrange of high temperature applications, reference should be made toSpecification A354.
Note3—For grades of alloy-steel bolting suitable for use in lowtemperature applications, reference should be made to SpecificationA320/A320M.
1.4 Nuts for use with bolting are covered in Section14.
1.5 Supplementary Requirements are provided for useat the option of the purchaser. The supplementary requirementsshall apply only when specified in the purchase order orcontract.
1.6 This specification is expressed in bothinch-pound units and in SI units; however, unless the purchaseorder or contract specifies the applicable M specification designation (SI units), theinch-pound units shall apply.
1.7 The values stated in either SI units orinch-pound units are to be regarded separately as standard. Withinthe text, the SI units are shown in brackets. The values stated ineach system may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.