Inconel 690 Washers manufactured at TorqBolt are corrosion resistant,high temperature resistant with ultimate tensile strength.
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 renowned as registered trademarks like Inconel,Incoloy,Incoloy Alloys. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. Inconel 690 Washers are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
Inconel Alloy 690 Is A High Chromium Inconel With Excellent Resistance To Many Corrosive Aqueous Media And High Temperature Atmosphere. Its High Chromium Content Gives It Excellent Resistance To Aqueous Corrosion By Oxidising Acids (especially Nitric Acid) And Salts And To Sulphidation At High Temperatures. In Addition To Its Corrosion Resistance, Alloy 690 Has High Strength, Good Metallurgical Stability And Favourable Fabrication Characteristics.
Inconel 690 washers distribute clamp load over a wider bearing area, prevent surface damage, and accommodate bolt-hole oversize. TorqBolt manufactures Inconel 690 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
Inconel 690 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
Inconel 690 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 Inconel 690 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.
Inconel — Nickel-Chromium Superalloys
Inconel alloys are nickel-chromium-based superalloys engineered for service where standard stainless steels cannot survive. The Inconel family combines high-temperature strength (typically retained up to 700-1100°C depending on grade) with outstanding oxidation and chloride-pitting resistance.
The most widely specified grade is Inconel 718, an age-hardenable Ni-Cr-Fe-Mo-Nb composition strengthened by γ' (Ni₃Al,Ti) and γ'' (Ni₃Nb) precipitates after solution + double-age heat treatment per AMS 5662 / 5663. Inconel 625 is solid-solution strengthened by Mo+Nb, supplied in the as-annealed condition, and weldable without post-weld heat treatment. Inconel X-750 uses Ti+Al precipitation hardening for spring + bolt applications to 700°C. Inconel 600 / 601 are general-purpose grades for furnace and heat-exchanger fasteners.
Typical specifications: ASTM B637 (forged bar), AMS 5662/5663 (rod/bar), ASTM B446 (625 bar), DIN 17752/17754 (round/forged). NACE MR0175 / ISO 15156 sour-service envelopes available on most grades when supplied in the correct heat-treat condition. PREN values for chloride pitting resistance typically exceed 50 across the Inconel range.
