Gunmetal G3 Lock washers manufactured at TorqBolt are wear and cavitation resistant with excellent impact properties.
Dimensional standards as per DIN 6797,DIN 6804 are provided.
The raw material of these fasteners is classified as Non-Ferrous Alloys. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. Gunmetal G3 Lock washers are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
Gunmetal G3 Lock washers distribute clamp load over a wider bearing area, prevent surface damage, and accommodate bolt-hole oversize. TorqBolt manufactures Gunmetal G3 Lock 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
Gunmetal G3 Lock 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
Gunmetal G3 Lock 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 Gunmetal G3 Lock 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.
Bronze alloys are copper-based alloys with tin, aluminium, silicon, manganese, or phosphorus alloying additions, each tuned for a specific tribological or environmental envelope. Bronzes deliver excellent bearing properties, marine corrosion resistance, and non-sparking + non-magnetic characteristics — specified for marine fasteners, electrical hardware, oil + gas wellhead components, and industries where sparks must be avoided.
Phosphor bronze (Cu-Sn-P, e.g. C51000, C52400) combines high yield strength + fatigue with seawater corrosion resistance — the standard for marine + spring fasteners. Silicon bronze (Cu-Si, e.g. C65500) is the marine-grade weldable alloy popular for boat fasteners and architectural cladding. Aluminium bronze (Cu-Al, e.g. C95400/C95500/C95800) achieves yield ~310-585 MPa with outstanding seawater + cavitation resistance — the workhorse for marine pump impellers and propeller hub bolting. Gunmetal (Cu-Sn-Zn-Pb, e.g. C90500) is the historic naval bronze for valves and trim. Leaded bronze adds Pb for free-machining + bearing applications.
Bronze fasteners ship per ASTM B98 (rod/bar) and B584 (sand cast) with EN 10204 3.1 / 3.2 certificates covering composition, hardness, and ASTM B66 ammonia stress-corrosion testing where service exposure warrants.
