Scope
ASTM A193 / A193M-19 is the current edition of the ASTM standard covering alloy steel and stainless steel bolting materials for pressure-vessel, valve, flange, and fitting service at high temperature, high pressure, or both. The specification scope covers bars, wire, bolts, screws, studs, and stud bolts in two parallel editions: A193 (imperial / inch-pound units) and A193M (metric / SI units). The 2019 edition supersedes A193/A193M-17 and is the latest published revision; ASME boiler code projects reference the same content under the SA-193 designation in ASME BPVC Section II Part A.
The standard organises bolting grades into two families: ferritic alloy steels (B5, B6, B6X, B7, B7M, B16) and austenitic stainless steels (B8, B8A, B8C, B8CA, B8M, B8MA, B8M2, B8M3, B8N, B8R, B8S, B8T, B8P, B8LN, B8MLN, B8MN, B8MLCUN, B8CLN, B8ML4CuN, plus the annealed-in-finished-condition A-suffix variants). Each grade is then supplied in one or more classes: Class 1 (solution annealed), Class 1A (annealed in the finished condition), Class 1B (extra-low carbon), Class 1C (high-nitrogen high-tensile), Class 1D (annealed and liquid quenched, heavier sections), Class 2 (annealed and strain hardened), Class 2B and Class 2C (larger-diameter strain hardened variants).
Where to procure the PDF
The ASTM A193/A193M-19 standard document is published by ASTM International and is not redistributed on third-party sites. Purchase the controlled PDF directly from astm.org, IHS Markit, or your national standards body (BSI for the UK, BIS for India, SAI Global for Australia). The standard runs approximately 22 pages and includes the grade-to-UNS cross-reference table, full chemistry envelope, and the class-vs-diameter mechanical-property tables cited on this site.
Certification routes
ASTM A193 supply is paired with one of two EN 10204 inspection certificate types. Type 3.1 is the standard mill MTC traceable to heat number, sufficient for non-critical and standard-strength procurement. Type 3.2 is the mill MTC counter-signed by an independent third-party inspector (DNV, TUV, Lloyd's Register, Bureau Veritas, or operator-nominated agency), required for sour-service positions under NACE MR0175, NORSOK-spec offshore equipment, ASME PED 2014/68/EU Category III pressure-equipment, and nuclear bolting. TorqBolt's manufacturing route is qualified to NORSOK M-650 Rev.4 for the high-alloyed austenitic stainless steel grades (B8, B8M, B8CLN family).
On this site
The astma193b8m.com micro-site focuses on the B8M family (UNS S31600 / 316 stainless): B8M overview, B8M Class 1, Class 1A, Class 1D, Class 2. Companion pages cover the ASME SA-193 designation, B8M vs B8 (316 vs 304) selection, and UNS S31600 material data.
