{"title":"DIN 137A Spring Washer (Curved) – 65Mn Steel Zinc CR3","description":"\u003ch1\u003eDIN 137A Curved Spring Washer — 65Mn Spring Steel, Zinc Plated CR3\u003c\/h1\u003e\n\n\u003cp\u003eFULLERKREG DIN 137A curved spring washers are manufactured to DIN 137 Type A standard in 65Mn high-manganese spring steel (per GB\/T 1222) with zinc electroplating and trivalent chromium (CR3) passivation. DIN 137 Type A is a curved (dished) spring washer with a larger outer diameter than DIN 128A, providing greater spring travel and higher load capacity for the same bolt size. 65Mn spring steel achieves 430–510 HV hardness after quench and temper. The zinc CR3 finish provides ≥72h salt spray resistance with full RoHS compliance — no hexavalent chromium.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNote on hydrogen embrittlement:\u003c\/strong\u003e At 430–510 HV, electroplating introduces hydrogen embrittlement risk. FULLERKREG applies mandatory post-plate baking (per ISO 9587 \/ GB\/T 13912) to eliminate this risk.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eProduct Highlights\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStandard:\u003c\/strong\u003e DIN 137 Type A (Curved Spring Washer)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e 65Mn Spring Steel (GB\/T 1222)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSurface Treatment:\u003c\/strong\u003e Zinc Electroplating + CR3 Trivalent Chromium Passivation\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCorrosion Resistance:\u003c\/strong\u003e ≥72h NSS per ISO 9227\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e 430–510 HV (approx. 44–50 HRC) after quench \u0026amp; temper\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSize Range:\u003c\/strong\u003e M3 – M36\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProfile:\u003c\/strong\u003e Type A — Curved \/ dished (larger OD than DIN 128A, greater spring travel)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRoHS Compliant\u003c\/strong\u003e — CR3, no Cr6+\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePost-plate baking\u003c\/strong\u003e — hydrogen embrittlement relief per ISO 9587\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDimensional Specifications — DIN 137 Type A (Curved), 65Mn Steel Zinc CR3\u003c\/h2\u003e\n\u003cp\u003eAll dimensions in mm. Per DIN 137 Type A.\u003c\/p\u003e\n\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eNominal Size\u003c\/th\u003e\n\u003cth\u003eFor Bolt\u003c\/th\u003e\n\u003cth\u003ed1 min\u003c\/th\u003e\n\u003cth\u003ed2 max\u003c\/th\u003e\n\u003cth\u003eh min\u003c\/th\u003e\n\u003cth\u003eh max\u003c\/th\u003e\n\u003cth\u003es (thickness)\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003ctd\u003eM3\u003c\/td\u003e\n\u003ctd\u003e3.2\u003c\/td\u003e\n\u003ctd\u003e7.5\u003c\/td\u003e\n\u003ctd\u003e0.8\u003c\/td\u003e\n\u003ctd\u003e1.2\u003c\/td\u003e\n\u003ctd\u003e0.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003eM4\u003c\/td\u003e\n\u003ctd\u003e4.3\u003c\/td\u003e\n\u003ctd\u003e9.5\u003c\/td\u003e\n\u003ctd\u003e1.0\u003c\/td\u003e\n\u003ctd\u003e1.4\u003c\/td\u003e\n\u003ctd\u003e0.6\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003ctd\u003eM5\u003c\/td\u003e\n\u003ctd\u003e5.3\u003c\/td\u003e\n\u003ctd\u003e11.5\u003c\/td\u003e\n\u003ctd\u003e1.2\u003c\/td\u003e\n\u003ctd\u003e1.7\u003c\/td\u003e\n\u003ctd\u003e0.8\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003eM6\u003c\/td\u003e\n\u003ctd\u003e6.4\u003c\/td\u003e\n\u003ctd\u003e14.0\u003c\/td\u003e\n\u003ctd\u003e1.5\u003c\/td\u003e\n\u003ctd\u003e2.1\u003c\/td\u003e\n\u003ctd\u003e1.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003ctd\u003eM8\u003c\/td\u003e\n\u003ctd\u003e8.4\u003c\/td\u003e\n\u003ctd\u003e18.0\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003ctd\u003e2.8\u003c\/td\u003e\n\u003ctd\u003e1.2\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e10\u003c\/td\u003e\n\u003ctd\u003eM10\u003c\/td\u003e\n\u003ctd\u003e10.5\u003c\/td\u003e\n\u003ctd\u003e22.0\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003ctd\u003e3.5\u003c\/td\u003e\n\u003ctd\u003e1.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e12\u003c\/td\u003e\n\u003ctd\u003eM12\u003c\/td\u003e\n\u003ctd\u003e13.0\u003c\/td\u003e\n\u003ctd\u003e26.0\u003c\/td\u003e\n\u003ctd\u003e3.0\u003c\/td\u003e\n\u003ctd\u003e4.2\u003c\/td\u003e\n\u003ctd\u003e1.8\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e14\u003c\/td\u003e\n\u003ctd\u003eM14\u003c\/td\u003e\n\u003ctd\u003e15.0\u003c\/td\u003e\n\u003ctd\u003e30.0\u003c\/td\u003e\n\u003ctd\u003e3.5\u003c\/td\u003e\n\u003ctd\u003e4.9\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e16\u003c\/td\u003e\n\u003ctd\u003eM16\u003c\/td\u003e\n\u003ctd\u003e17.0\u003c\/td\u003e\n\u003ctd\u003e34.0\u003c\/td\u003e\n\u003ctd\u003e4.0\u003c\/td\u003e\n\u003ctd\u003e5.6\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e20\u003c\/td\u003e\n\u003ctd\u003eM20\u003c\/td\u003e\n\u003ctd\u003e21.0\u003c\/td\u003e\n\u003ctd\u003e42.0\u003c\/td\u003e\n\u003ctd\u003e5.0\u003c\/td\u003e\n\u003ctd\u003e7.0\u003c\/td\u003e\n\u003ctd\u003e3.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e24\u003c\/td\u003e\n\u003ctd\u003eM24\u003c\/td\u003e\n\u003ctd\u003e25.0\u003c\/td\u003e\n\u003ctd\u003e50.0\u003c\/td\u003e\n\u003ctd\u003e6.0\u003c\/td\u003e\n\u003ctd\u003e8.4\u003c\/td\u003e\n\u003ctd\u003e3.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e30\u003c\/td\u003e\n\u003ctd\u003eM30\u003c\/td\u003e\n\u003ctd\u003e31.0\u003c\/td\u003e\n\u003ctd\u003e62.0\u003c\/td\u003e\n\u003ctd\u003e7.5\u003c\/td\u003e\n\u003ctd\u003e10.5\u003c\/td\u003e\n\u003ctd\u003e4.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e36\u003c\/td\u003e\n\u003ctd\u003eM36\u003c\/td\u003e\n\u003ctd\u003e37.0\u003c\/td\u003e\n\u003ctd\u003e74.0\u003c\/td\u003e\n\u003ctd\u003e9.0\u003c\/td\u003e\n\u003ctd\u003e12.6\u003c\/td\u003e\n\u003ctd\u003e5.0\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eMaterial Properties — 65Mn Spring Steel (GB\/T 1222)\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eProperty\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMaterial Grade\u003c\/td\u003e\n\u003ctd\u003e65Mn Spring Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eC Content\u003c\/td\u003e\n\u003ctd\u003e0.62 – 0.70%\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMn Content\u003c\/td\u003e\n\u003ctd\u003e0.90 – 1.20%\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHardness\u003c\/td\u003e\n\u003ctd\u003e430–510 HV (44–50 HRC)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTensile Strength\u003c\/td\u003e\n\u003ctd\u003e1275 MPa min.\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSurface\u003c\/td\u003e\n\u003ctd\u003eZinc CR3, 5–12 um, ≥72h NSS\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eH2 Embrittlement\u003c\/td\u003e\n\u003ctd\u003ePost-plate baking per ISO 9587\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRoHS \/ REACH\u003c\/td\u003e\n\u003ctd\u003eCompliant — CR3, no Cr6+\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDIN 137A vs. DIN 137B\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eType A (Curved)\u003c\/th\u003e\n\u003cth\u003eType B (Crinkled)\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eProfile\u003c\/td\u003e\n\u003ctd\u003eSingle curved arc\u003c\/td\u003e\n\u003ctd\u003eMultiple corrugations\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eContact\u003c\/td\u003e\n\u003ctd\u003eContinuous curved\u003c\/td\u003e\n\u003ctd\u003eMulti-point\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eBest for\u003c\/td\u003e\n\u003ctd\u003eHigh load, smooth bearing surface\u003c\/td\u003e\n\u003ctd\u003eGeneral assemblies\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eApplication Scenarios\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eHigh-load bolted assemblies — larger OD vs. DIN 128A, greater spring travel\u003c\/li\u003e\n  \u003cli\u003eHeavy machinery \u0026amp; industrial equipment — outdoor corrosion protection\u003c\/li\u003e\n  \u003cli\u003eAutomotive — chassis and underbody exposed to moisture\u003c\/li\u003e\n  \u003cli\u003eConstruction \u0026amp; steel structures — sheltered outdoor environments\u003c\/li\u003e\n  \u003cli\u003eAgricultural \u0026amp; mining equipment — high-vibration, humid conditions\u003c\/li\u003e\n  \u003cli\u003eSoft material assemblies — no sharp edges, no surface marking\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eProduct Photo Gallery\u003c\/h2\u003e\n\u003cp\u003eFULLERKREG DIN 137A Curved Spring Washer, 65Mn Spring Steel, Zinc CR3:\u003c\/p\u003e\n\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\n  \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 1 ]\u003c\/td\u003e\n  \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 2 ]\u003c\/td\u003e\n  \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 3 ]\u003c\/td\u003e\n  \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 4 ]\u003c\/td\u003e\n\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy Choose FULLERKREG?\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e🏭 \u003cstrong\u003eDirect manufacturer\u003c\/strong\u003e — factory in China, no middlemen\u003c\/li\u003e\n  \u003cli\u003e📐 \u003cstrong\u003eStrict DIN dimensional control\u003c\/strong\u003e — 100% inspection on critical dimensions and hardness\u003c\/li\u003e\n  \u003cli\u003e🌍 \u003cstrong\u003eGlobal export experience\u003c\/strong\u003e — Europe, North America, Southeast Asia\u003c\/li\u003e\n  \u003cli\u003e📦 \u003cstrong\u003eFlexible MOQ\u003c\/strong\u003e — trial orders and bulk shipments welcome\u003c\/li\u003e\n  \u003cli\u003e📋 \u003cstrong\u003eFull documentation\u003c\/strong\u003e — mill certs, hardness reports, salt spray reports, RoHS declarations\u003c\/li\u003e\n  \u003cli\u003e⚡ \u003cstrong\u003eFast lead times\u003c\/strong\u003e — standard sizes in stock\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eFAQ\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What is CR3 passivation?\u003c\/strong\u003e\u003cbr\u003eA: Trivalent chromium passivation over zinc electroplating. Provides ≥72h NSS corrosion protection without Cr6+. Fully RoHS compliant.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How is hydrogen embrittlement managed?\u003c\/strong\u003e\u003cbr\u003eA: Post-plate baking at 190–220°C for 4–8 hours per ISO 9587 drives off absorbed hydrogen before the zinc coating seals.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: DIN 137A vs. DIN 128A?\u003c\/strong\u003e\u003cbr\u003eA: DIN 137A has larger OD and greater spring travel for the same bolt size. DIN 128A is designed for cheese head and pan head screws with smaller OD.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Certificates available?\u003c\/strong\u003e\u003cbr\u003eA: Yes. Mill certs, hardness reports, salt spray reports, RoHS declarations on request.\u003c\/p\u003e\n\n\u003chr\u003e\n\u003cp\u003e\u003cstrong\u003eFULLERKREG Fasteners\u003c\/strong\u003e — Precision DIN Standard Fasteners, Direct from Manufacturer.\u003cbr\u003eFor wholesale inquiries, technical questions, or custom orders, please contact our sales team.\u003c\/p\u003e","products":[],"url":"https:\/\/www.fullerkr.com\/collections\/din-137a-spring-washer-curved-65mn-steel-zinc-cr3.oembed","provider":"Fullerkreg Fasteners","version":"1.0","type":"link"}