ASTM A193/A193M is a specification from the ASTM International that primarily govern industrial piping applications. In the assembly of an industrial plant, many complex components are bolted together of which include parts such as valves, piping, and pressure vessels. ASTM A193 defines the methodology to procure and certify externally threaded fasteners according to specific chemical and mechanical criteria. It is standards such as this that allow industrial process applications to be safely engineered so they do not exceed the tensile strength of the fasteners that hold them together.[1]
ASTM A193 / A193M-17, Standard Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service and Other Special Purpose Applications, ASTM International, West Conshohocken, PA, 2017, www.astm.org. ASTM A193 Grade B7 is a standard material specification for chromium-molybdenum alloy steel fasteners for use in high tensile, high temperature and special purpose applications. Grade B7 is a heat-treated chromium-molybdenum alloy steel with minimum tensile requirement of 100 ksi, yield of 75 ksi and maximum hardness of 35 HRC. It covers material specification for bolting used in pressure vessel service, valves, flanges and fittings. ASTM A193 defines both SI (Metric) and inch-pound units. Grade B7 is a heat-treated chromium-molybdenum (Cr-Mo) alloy steel with minimum tensile strength requirement of 125 ksi, yield 105 ksi, and maximum hardness of 35HRC.
Material grades that are governed under ASTM A193 include:
Grade: UNS designation[clarification needed]
- B5 5% Chromium
- B6 12% Chromium
- B6X S 41000
- B7 Chromium-molybdenum steel
- B7M Chromium-molybdenum
- B16 Chromium-molybdenum-vanadium steel
Grade: UNS designation
- B8 S 30400 (304)
- B8A S 30400 (304)
- B8C S 34700 (347)
- B8CA S 34700 (347)
- B8M S 31600 (316)
- B8MA S 31600 (316)
- B8M2 S 31600 (316)
- B83 S 31600 (316)
- B8P S 30500
- B8PA S 30500
- B8N S 30451 (304N)
- B8NA S 30451 (304N)
- B8MN S 31651 (316N)
- B8MNA S 31651 (316N)
- B8MLCuN S 31254
- B8MLCuNA S 31254
- B8T S 32100 (321)
- B8TA S 32100 (321)
- B8R S 20910
- B8RA S 20910
- B8S S 21800
- B8SA S 21800
- B8LN S 30453
- B8LNA S30453
- B8MLN S 31653
- B8MLNA S 31653
References[edit]
- ^'ASTM A193 / A193M - 16 Standard Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service and Other Special Purpose Applications'. www.astm.org. Retrieved 15 February 2017.