Hastelloy B3 Spring Washers Specification

Hastelloy B3 Equivalent Designation
| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| N10675 | – | – | – | – | – |
Hastelloy B3 Spring washers distribute clamp load over a wider bearing area, prevent surface damage, and accommodate bolt-hole oversize. TorqBolt manufactures Hastelloy B3 Spring washers per ASME B18.21.1 / B18.22.1, DIN 125 / 126 / 127 / 9021, and ISO 7089 / 7090 / 7093 / 7094, in metric (M3–M100) and imperial (#4–4") sizes.
Hastelloy B3 Spring plain washers are characterized by three critical dimensions: ID (clearance over bolt diameter), OD (load distribution area), and thickness (compressive stiffness). Standard tolerances are h13 on OD and H13 on ID per ISO 286-2; flatness 0.05 mm/100 mm and parallelism 0.05 mm/100 mm verified per lot. Edge break / chamfer per drawing.
Hastelloy B3 Spring washers are hardness-controlled to balance load-distribution stiffness against surface damage to mating parts. Typical Vickers HV ranges: plain 140–180 HV; spring 380–440 HV; Belleville 460–540 HV. Surface finish Ra 1.6 µm or better; on critical sealing applications, Ra 0.8 µm available.
TorqBolt produces Hastelloy B3 Spring washers in square (DIN 436), fender (oversized OD), tab / lock-tang (DIN 462 / 463), and spherical seat washer + cup combinations. EN 10204 3.1 / 3.2 material certificates standard; NACE MR0175 / ISO 15156 on request.
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.