ASTM A193/A193M-24a PDF

Full title and description

ASTM A193/A193M‑24a — Standard Specification for Alloy‑Steel and Stainless Steel Bolting for High Temperature or High Pressure Service and Other Special Purpose Applications. This specification defines chemical, mechanical, heat‑treatment, and testing requirements for alloy‑steel and stainless‑steel bolts, studs and other bolting components intended for high‑temperature or high‑pressure service (pressure vessels, valves, flanges, fittings and similar applications).

Abstract

A193/A193M‑24a is a short (14‑page) ASTM specification that establishes grades, classes, required heat treatment, chemical composition limits, mechanical property minima (tensile, yield, elongation, hardness) and testing/inspection practices for high‑temperature/high‑pressure bolting made from alloy and stainless steels. It is referenced by other ASTM bolting and fastener standards and is available in both inch‑pound and SI unit designations (A193 and A193M).

General information

• Status: Historical / superseded (replaced by ASTM A193/A193M‑25, published May 1, 2025).
• Publication date: October 15, 2024 (designation 24a).
• Publisher: ASTM International.
• ICS / categories: 21.060.01 (Fasteners in general); 77.080.20 (Steels).
• Edition / version: 24a (revision of the 2024 edition).
• Number of pages: 14.

Scope

This specification covers alloy and stainless steel bolting materials and bolting components (bar, wire, finished bolts, studs, and related parts) intended for pressure vessels, valves, flanges, fittings and other special‑purpose applications where high temperature or high pressure service is expected. The standard specifies allowable grades and classes, required heat treatments (including solution treatment for austenitic grades), chemical composition limits, and mechanical property and hardness requirements; it also references common bolting requirements in A962/A962M.

Key topics and requirements

• Designation of ferritic and austenitic grades and classes (examples: B5, B6, B7, B7M, B8, B8M, B16, etc.).
• Chemical composition limits for each grade and class (detailed element percentages by grade).
• Heat treatment and tempering/stress‑relief requirements (including carbide solution treatment for austenitic grades and minimum tempering temperatures for ferritic grades).
• Mechanical property minima: tensile strength, yield (0.2% offset), elongation, reduction of area and maximum hardness limits by diameter/class.
• Testing and inspection: tensile testing, hardness tests, full‑size fastener or wedge tensile testing where required, and requirements that reference A962/A962M for common bolting provisions.
• Optional supplementary requirements and purchaser‑specified provisions (surface finishes/coatings, special testing, metric vs. inch‑pound designations).
• Administrative/technical updates (24a included editorial/technical changes later addressed in the 2025 revision via committee work items).

Typical use and users

Engineers, procurement/specification writers, fabricators and manufacturers of pressure vessels, piping, valves and flanged assemblies; fastener and bolt producers; quality and inspection personnel; and code authorities who specify bolting for high‑temperature/high‑pressure service commonly use this standard to select bolt grades, define manufacturing and testing requirements, and ensure interchangeability and safety in critical applications.

Related standards

Commonly referenced and related documents include ASTM A962/A962M (common bolting requirements), ASTM A194/A194M (nuts for high‑pressure/high‑temperature service), ASTM A320/A320M (low‑temperature bolting), ASTM A354 (quenched and tempered alloy steel bolts), ASTM A563 (nuts), and various ASTM test methods referenced within A193 (tensile, hardness, metallography, etc.).

Keywords

bolting; high temperature; high pressure; alloy steel; stainless steel; bolts; studs; heat treatment; tempering; tensile strength; hardness; A193; A193M; A962.

FAQ

Q: What is this standard?

A: ASTM A193/A193M‑24a is an ASTM specification that sets requirements for alloy‑steel and stainless‑steel bolting intended for high‑temperature or high‑pressure service and other special‑purpose applications.

Q: What does it cover?

A: It covers grade/class designations, chemical composition limits, heat treatment and tempering requirements, mechanical property minima (tensile, yield, elongation, hardness), and testing/inspection procedures for bolting components used in pressure‑containing and other critical applications.

Q: Who typically uses it?

A: Design and mechanical engineers, fastener manufacturers, fabricators of pressure vessels and piping, procurement/spec writers, and QA/QC inspectors use this standard to specify and verify bolting for critical services.

Q: Is it current or superseded?

A: A193/A193M‑24a was published October 15, 2024 and is now superseded by ASTM A193/A193M‑25 (published May 1, 2025); users should reference the 2025 edition for current requirements unless a project or contract specifically mandates 24a.

Q: Is it part of a series?

A: Yes — A193/A193M is part of a family of bolting and fastener standards that include A962/A962M (common bolting requirements), A194/A194M (nuts), A320/A320M (low‑temperature bolting), A354, A563 and other related ASTM specifications and test methods.

Q: What are the key keywords?

A: Bolting, alloy steel, stainless steel, high temperature, high pressure, grades B5/B6/B7/B8/B16, heat treatment, tensile, hardness, A193, A193M, A962.