A286 Stainless Steel Washers manufactured at TorqBolt are high temperature and high strength iron based with high oxidation resistance.
Dimensional standards as per DIN 125,ISO 7089,ISO 7090,ISO 7092,DIN 433,DIN 7349,DIN 9021,ISO 7093, are provided.
The raw material of these fasteners is classified as High temperature Austenitic Stainless Steel. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. A286 Stainless Steel Washers are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
A286 stainless steel Fasteners are referred as high temperature bolting with co-efficient expansion similar to Austenitic Stainless Steel. A286 material specification is achieved by producing A286 steel in Argon oxygen decarburization (AOD) or vacuum Induction Melting Process that is further refined by Vacuum Arc Refining (VAR) or Electro Slag Refining (ESR) used for high nickel alloys like incoloy alloys. Comparable to incoloy, A286 can be age hardened with both oil quench and liquid quench conditions. Unlike other precipitation hardening steels, this A286 Steel requires Stress Rupture Testing with 100 hours minimum time to rupture. High temperature and low stress applications, good corrosion resistance at high temperatures are some of the most A286 Stainless Steel Properties. A286 steel is available in both solution treated condition and age hardened conditions.
A286 Stainless Steel washers distribute clamp load over a wider bearing area, prevent surface damage, and accommodate bolt-hole oversize. TorqBolt manufactures A286 Stainless Steel 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.
Plain Washer Dimensions
A286 Stainless Steel 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.
Form Variants
Form A (regular) — DIN 125-A / ISO 7089, the default plain washer
Form B (large OD) — DIN 9021 / ISO 7093, for soft mating surfaces
Form C (heavy) — DIN 7349 / ISO 7094, for slotted holes / structural use
Spring (split) — DIN 127 / ASME B18.21.1, helical anti-vibration
Conical / Belleville (DIN 6796 / 2093) — preload maintenance
Hardness & Surface
A286 Stainless Steel 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.
Special Patterns
TorqBolt produces A286 Stainless Steel 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.
A286 — Iron-Nickel-Chromium Superalloy
A-286 (UNS S66286, AISI 660) is an iron-nickel-chromium age-hardenable superalloy positioned between austenitic stainless steels and Inconel for high-temperature bolting at 700-1300°F (370-700°C). Approximately 26% Ni + 15% Cr + 1.25% Mo with Ti-Al precipitation hardening, A-286 retains tensile strength and oxidation resistance well beyond the limits of standard 316 SS while being substantially more economical than full nickel superalloys.
A-286 is the standard high-temperature stud and bolt material for steam turbines, gas-turbine combustor cases, exhaust systems, jet-engine shafts, and superheater bolting. The alloy responds to a two-step heat treatment: solution anneal at 980°C (water quench) followed by ageing at 720°C for ~16 hours, yielding tensile ~895 MPa and yield ~585 MPa with elongation >15%.
A-286 fasteners are supplied per ASTM A453 grade 660 (with class A/B/C/D heat-treat conditions) and AMS 5731 / 5732 / 5734 / 5737. EN 10204 3.1 / 3.2 certification covers chemistry, mechanicals at room temperature + elevated test temperatures, hardness (HRC 24-35), and stress-rupture testing. NACE MR0175 / ISO 15156 sour-service compliance is achievable in specific heat-treat conditions; A-286 is widely qualified for downhole + wellhead bolting.
