Hexagon Bolts
- ANSI B18.2.1
- ANSI B18.2.3.1M
- DIN 931
- DIN 933
- BS 1768
- UNI 5731
- UNI 5737
- UNI 5739
- ISO 4014
- ISO 4017
- BS 1769
- BS 3692
AISI 348 Stainless Steel is a high-performance alloy used wherever standard fasteners cannot meet the corrosion, temperature, or strength envelope. TorqBolt manufactures the full AISI 348 Stainless Steel fastener range — bolts, nuts, screws, washers, studs, and custom forgings — under one ISO 9001:2015 quality system, with PED 2014/68/EU module-H qualification for pressure-equipment service.
AISI 348 Stainless Steel is specified in oil & gas wellhead components, refinery heat exchangers, petrochemical reactors, power-generation turbines, marine offshore platforms, and pharmaceutical / food-grade processing. Its corrosion resistance, high-temperature strength, and weldability make it the default for service conditions outside the carbon and standard-stainless envelope.
AISI 348 Stainless Steel fasteners are supplied with EN 10204 3.1 (mill cert) or 3.2 (third-party witnessed) material test reports as standard. Additional certification packages: NACE MR0175 / ISO 15156 (sour service), NORSOK M-650 (subsea / topside), API 6A (wellhead), API 20E (subsea bolting), PED 2014/68/EU (pressure equipment). Third-party inspection by TUV, Lloyd's, BV, DNV, SGS, and Intertek arrangeable on order.
Stock items in standard AISI 348 Stainless Steel fastener sizes ship in 1–2 weeks; custom-manufactured items in 4–6 weeks subject to material availability. Diameters M6–M100 and 1/4"–4", lengths 10 mm–3000 mm covered in-house; oversize / non-standard sizes quoted to specification.
Austenitic stainless steels form the workhorse 300-series — face-centered cubic Fe-Cr-Ni alloys delivering excellent corrosion resistance, formability, weldability, and toughness from cryogenic to ~600°C. They are non-magnetic in the annealed condition and the default choice for food, dairy, pharmaceutical, marine, and general process-industry fasteners.
AISI 304 (18Cr-8Ni, UNS S30400) is the baseline; 304L (low-C) prevents weld sensitization for thicker sections. AISI 316 adds 2-3% Mo for chloride pitting resistance, and 316L is the welding-grade marine standard. 309 / 310 are the high-Cr grades for elevated temperatures (to ~1100°C). 321 / 347 are Ti / Nb-stabilized for stress-relieved welded service. 304LN / 316LN add nitrogen for higher yield without sacrificing corrosion.
Austenitic fasteners are supplied per ASTM A193 grade B8 (304), B8M (316), B8T (321), B8C (347) and ASTM A276 / A479 for general bar. EN 10204 3.1 / 3.2 certs cover mechanicals, hardness (HB ~150-217), intergranular-corrosion testing (ASTM A262 Practice E), and surface condition. NACE MR0175 sour-service compliance maintained below the hardness threshold for SSC.