Titanium Grade 2 Lock Washers Specification

Titanium Grade 2 Equivalent Designation
| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| R50400 | – | 3.7035 | – | – | – |
Titanium Grade 2 Lock washers distribute clamp load over a wider bearing area, prevent surface damage, and accommodate bolt-hole oversize. TorqBolt manufactures Titanium Grade 2 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.
Titanium Grade 2 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.
Titanium Grade 2 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.
TorqBolt produces Titanium Grade 2 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.
Titanium alloys deliver an exceptional strength-to-weight ratio (density ~4.5 g/cm³, half of steel) combined with outstanding seawater + chloride corrosion resistance — the spontaneously-formed TiO₂ surface film is impervious to chlorides and most oxidizing acids. Titanium is the default for marine offshore, desalination, chemical-process, and aerospace fasteners requiring weight reduction with corrosion immunity.
Grade 2 commercially-pure (CP-Ti) is the workhorse: yield ~275 MPa, fully formable, weldable, the standard for heat-exchanger tubing and chloride-service bolting. Grade 5 (Ti-6Al-4V) is the alpha-beta alloy delivering yield ~828 MPa after solution + age treatment per AMS 4928 / ASTM B348 — the dominant aerospace + medical grade. Grade 7 / Grade 11 add Pd for crevice + reducing-acid resistance. Grade 9 (Ti-3Al-2.5V) is the high-strength tubing alloy. Grade 12 (Ti-Mo-Ni) trades strength for hot-brine corrosion performance.
Titanium fasteners ship per ASTM B348 (Grade 2 / 5) and AMS 4928 / 4965 with EN 10204 3.1 / 3.2 certificates including hydrogen (≤ 125 ppm), oxygen, and tensile testing. Welding requires inert-gas shielding (back-purged Ar) to prevent embrittlement. NACE MR0175 sour-service is fully qualified across all common grades.