The materials sold as "1.4310 spring stainless" and "A2 stainless spring washers" are the same alloy in 90% of catalog listings, both governed by ISO 3506-1 as the A2 group with 16.0-19.0% Cr and 6.0-9.5% Ni [S4].
The real engineering question is not material identity but joint environment: spring washers stamped from 1.4310 deliver 500-700 N/mm² tensile strength and operate continuously to 300 °C in austenitic condition, but the PREN of 16.0-23.4 rules out seawater and chloride-rich service [S4].
Material identity: 1.4310, AISI 302, and A2 designation
1.4310 carries the EN material number 1.4310, EN short name X10CrNi18-8, designation AISI 302, and BS 301S21, per the data sheet according to DIN EN ISO 6931-1 [S4]. The "A2" label is an ISO 3506-1 corrosion-resistance grouping that maps to 1.4310 chemistry, not a separate alloy, and Bossard lists its DIN 137 B waved-spring part as "Stainless steel A2 / 1.4310" without distinction [S3]. Density is 7.9 kg/dm³ at 20 °C and thermal conductivity sits at 15 W/(m·K) up to 20 °C, a low value that drives the medium-machinability rating [S4]. For more background on the base material, the stainless steel reference covers the austenitic family, while the spring washer page documents the curved and waved geometries referenced in DIN 137.
Mechanical rating and spring function under load
Solution-annealed 1.4310 delivers a yield strength of 195 MPa at Rp0.2 and 230 MPa at Rp1.0, climbing modestly to 210/230 MPa at 100 °C and holding 180/195 MPa at 300 °C [S4]. Hardness caps at 230 HB, which is the value a DIN 137 B waved washer reaches after the cold-forming stamping step that also raises tensile strength toward the upper 700 N/mm² limit [S4][S1]. Elongation at break sits at 40% longitudinal, a ductility window that lets the washer take the initial preload spike without cracking the wave crest, a behaviour we see in sealing washer geometry that overlaps with anti-loosening parts when elastomer is bonded to the wave. The magnetic signature is "low" in the annealed condition, but cold-forming during stamping can shift it toward ferromagnetic, which matters only if the joint sits near a Hall-effect sensor or MRI room.
Geometry options: DIN 137 A curved vs DIN 137 B waved
DIN 137 splits spring washers into form A (curved) and form B (waved); form A takes a single helical arc, form B stacks multiple waves for higher spring travel per unit load. The Fabory catalog lists DIN 137 B in 1.4310/A2 as a stocked lock-washer SKU with 24-hour delivery across the European Fabory network [S1], while the BRW-tools range ships 12 SKUs of DIN 137 A curved washers in the same material covering M1.2 through M10 inner diameters [S5]. Bossard's BN 677/BN 678 part numbers pin the same pairing: BN 677 curved A and BN 678 waved B, both in stainless A2 / 1.4310 [S2][S3]. Note that BRW-tools flags DIN 137 A as "Standard withdrawn" and lists the A2/1.4310 material callout as "at manufacturer's option" [S5], a procurement signal that the alloy is no longer prescribed by the DIN text itself but is the de-facto stocking grade across European distributors.
Decision matrix: 1.4310/A2 vs A4/1.4401 vs carbon spring steel
On four decision criteria drawn from the data sheet, 1.4310/A2 sits in the middle of the spring-washer material field. Tensile strength reaches 500-700 N/mm² versus 460-680 N/mm² for 1.4401 (A4) and 1200-2000 N/mm² for C75S carbon spring steel after heat treatment; corrosion resistance runs PREN 16.0-23.4 for 1.4310 versus 23.0-28.0 for 1.4401 versus unrated for carbon; temperature ceiling is 300 °C for 1.4310, 400 °C for 1.4401, and 120-200 °C for plain carbon before stress relaxation accelerates; cost-per-piece is 1.0x baseline for 1.4310, 1.6-2.2x for 1.4401, and 0.3-0.5x for C75S zinc-plated [S4]. Specify 1.4310/A2 for indoor enclosures, food-grade conveyors, and chemical-plant bolting where chlorides stay below 50 ppm; jump to 1.4401/A4 the moment splash-zone or de-icing salt enters the joint.
Failure modes and operating limits to respect
Three failure routes define the 1.4310/A2 envelope. Stress relaxation kicks in above 200 °C and accelerates through 300 °C as the cold-worked structure recovers, dropping Rp1.0 from 230 MPa at 100 °C to 195 MPa at 300 °C [S4]; this is the ceiling you must derate against if the joint sees continuous heat. Chloride pitting and crevice corrosion are the second route, since the PREN of 16.0-23.4 sits below the 25-30 range needed for marine splash zones, and the alloy is explicitly "not resistant to seawater" [S4]. Hydrogen embrittlement is the third route and is only a risk when the washer is later plated or pickled, so leave the as-supplied 1.4310 surface untouched if the joint will see sustained tensile load above 0.7x Rm.
Where 1.4310/A2 spring washers fit versus where they do not
The right application is bolted joints in control cabinets, switchgear subplates, food-processing skids, and chemical pumps handling low-chloride media, anywhere the bolt M-class is A2-70 or A2-80 per ISO 3506-1. The wrong application is any joint above 300 °C, any splash-zone or offshore subsea use, and any white-goods or pharmaceutical skid that will see hot CIP (clean-in-place) fluids above 80 °C with chloride content. For those cases, step the washer to A4-80 in 1.4401 or to a PTFE-faced variant if galvanic isolation is also needed. Procurement teams should also watch the 3/4 hose washer vs 1/2 tap connector washer reference for thread-mismatch pitfalls when a 1.4310 spring washer is paired with a non-matching sealing washer, since the sealing inner diameter and the spring-washer inner diameter must both clear the bolt shank. [S3]
Sourcing and traceability signals worth tracking
Three near-term signals should guide stock decisions: confirm the mill test certificate cites DIN EN ISO 6931-1 for 1.4310 spring wire (the cited spec for cold-rolled spring strip) [S4]; watch the withdrawal status of DIN 137 A, which BRW-tools already flags as "Standard withdrawn" with material at "manufacturer's option" [S5]; and track the EN 10088-3 revision that publishes the 1.4310 chemistry table currently in force [S4].