15-5 Ph Stainless Steel Spring Washers Specification
15-5 Ph Stainless Steel Spring Washers manufactured at TorqBolt are high strength, good corrosion resistance, good mechanical properties at temperatures up to 600°F (316°C).
Dimensional standards as per DIN 127,DIN 128,DIN 275 are provided.
The raw material of these fasteners is classified as Martensitic Precipitation Hardening stainless steel. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. 15-5PH Spring Washers are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
15 5 PH Stainless Steel Spring washers distribute clamp load over a wider bearing area, prevent surface damage, and accommodate bolt-hole oversize. TorqBolt manufactures 15 5 PH Stainless Steel 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.
Plain Washer Dimensions
15 5 PH Stainless Steel 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.
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
15 5 PH Stainless Steel 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.
Special Patterns
TorqBolt produces 15 5 PH Stainless Steel 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.
Precipitation-Hardening (PH) Stainless Steels
Precipitation-hardening (PH) stainless steels combine the corrosion resistance of austenitic stainless with the high strength of martensitic grades. A two-step heat treatment — solution anneal followed by ageing at 480-620°C — precipitates Cu, Ti, or Al-rich phases that lock the matrix at tensile strengths up to 1300 MPa with minimal distortion.
17-4 PH (UNS S17400 / AMS 5643) is the dominant grade: Cu-precipitation hardened, with corrosion roughly equivalent to AISI 304. Five standard ageing conditions H900 (highest strength), H925, H1025, H1075, H1150 trade strength against fracture toughness. 15-5 PH (S15500) is the through-thickness-tougher variant with reduced delta-ferrite. 13-8 PH (S13800) and 17-7 PH (S17700) are higher-strength variants for aerospace + spring fasteners.
PH fasteners are supplied per ASTM A693 / AMS 5643 with EN 10204 3.1 / 3.2 certification including hardness (HRC 32-48 by condition), tensile, and Charpy impact. NACE MR0175 service for PH grades is restricted to specific heat-treat conditions (H1150 only for 17-4) due to SSC susceptibility. Welding requires post-weld solution + age cycle to recover full strength.
