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
Hastelloy G 35 is a high-performance alloy used wherever standard fasteners cannot meet the corrosion, temperature, or strength envelope. TorqBolt manufactures the full Hastelloy G 35 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.
Hastelloy G 35 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.
Hastelloy G 35 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 Hastelloy G 35 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.
Hastelloy is the trade designation for a family of nickel-chromium-molybdenum (and nickel-molybdenum) alloys formulated for severe wet-corrosion service: hydrochloric acid, sulfuric acid, chloride pitting, crevice corrosion, and sour wells.
Hastelloy C-276 (UNS N10276) is the workhorse: ~16% Cr, 16% Mo, 4% W gives unmatched resistance to oxidizing + reducing chloride media, the only nickel alloy resistant to wet chlorine + hypochlorite. Hastelloy C-22 (N06022) is upgraded with higher Cr for better oxidizing-acid performance. Hastelloy C-2000 (N06200) adds Cu for superior performance across the full pH range. Hastelloy B-3 (N10675) is Ni-Mo for hot HCl service. Hastelloy G-35 (N06035) targets phosphoric-acid plants.
Hastelloy fasteners ship per ASTM B574 / B575 (rod/bar/plate), with EN 10204 3.1 / 3.2 certification including PMI and intergranular-corrosion testing per ASTM G28. The ASTM A193 grade B14 + B7M designations cover Hastelloy bolting for ASME pressure-vessel use. NACE MR0175 / ISO 15156 sour-service compliance is standard. Welding requires matching filler metal (Ernicrmo-4 for C-276) with no post-weld solution anneal.