This specification covers the chemical and mechanical requirements for stainless steel and nickel alloy bolts, hex cap screws, and studs intended for use in applications where resistance to heat and the effects of high temperature are to be considered.

Three types of materials covered in this specification are:

• Type I— heat resisting alloys for continuous service applications;
• Type II— heat resisting alloys for continuous and intermittent service applications; and
• Type III— high temperature alloys for continuous and intermittent service applications.

Type I is classified further into:

• Class A— austenitic grades,
• Class B— martensitic grades, and
• Class C— ferritic grades.

Type III is also classified further into:

• Class A— nickel based alloy,
• Class B— precipitation hardened alloy, and
• Class C— precipitation hardened alloy.

The products shall be subject to:

• chemical analysis;
• mechanical tests to determine yield strength, wedge tensile strength, or axial tensile strength; and
• corrosion resistance tests to determine freedom from precipitated carbides.

1.1 This specification covers the chemical and mechanical requirements for stainless steel and nickel alloy bolts, hex cap screws, and studs, ¹/₄ in. diameter and larger, intended for use at temperatures up to 1800°F (982°C), and in applications where resistance to heat and the effects of high temperature are to be considered.

See Appendix X1 for Service Application.

A wide variety of materials are covered in this specification which can be used at high temperatures as a function of the specific alloy properties, as well as environmental requirements including corrosive environments.

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 standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4 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.