{"title":"DIN 6921 Class 8.8 Hex Flange Bolt Zinc Finish","description":"\u003ch1\u003eDIN 6921 Hex Flange Bolt — Class 8.8 | Zinc CR3 Finish | FULLERKREG\u003c\/h1\u003e\n\n\u003cp\u003eFULLERKREG DIN 6921 Class 8.8 Hex Flange Bolts deliver reliable, high-strength fastening for automotive and new energy vehicle (NEV) assemblies. Manufactured at our Wuhu, Anhui facility — situated in China's premier automotive manufacturing hub, home to Chery Automobile — these bolts are produced to the full dimensional and mechanical requirements of DIN 6921 and DIN EN ISO 898-1, with a RoHS-compliant Zinc CR3 (trivalent chromate) surface finish per DIN 267-11.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eProduct Overview\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStandard:\u003c\/strong\u003e DIN 6921\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Hexagon Flange Bolt (with or without serration)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Alloy Steel 10B21 (boron steel) or Carbon Steel 35K\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProperty Class \/ Grade:\u003c\/strong\u003e 8.8 (per DIN EN ISO 898-1)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSurface Treatment:\u003c\/strong\u003e Zinc CR3 (trivalent chromate zinc electroplate)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread:\u003c\/strong\u003e Metric coarse thread (ISO 68-1)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e FULLERKREG\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturing Origin:\u003c\/strong\u003e Wuhu, Anhui, China\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eTwo Flange Head Types Available\u003c\/h2\u003e\n\n\u003ch3\u003e① Non-Serrated Flange (Smooth Flange)\u003c\/h3\u003e\n\u003cp\u003eThe standard DIN 6921 configuration featuring a smooth, flat flange underhead bearing surface. The enlarged flange diameter distributes clamping load over a wider area, reducing surface pressure on the joint and eliminating the need for a separate washer in most applications.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSmooth flange underside — no surface marking on mating parts\u003c\/li\u003e\n  \u003cli\u003eLarge bearing area reduces contact stress on softer substrates\u003c\/li\u003e\n  \u003cli\u003eSuitable for painted panels, aluminium castings, and plastic brackets\u003c\/li\u003e\n  \u003cli\u003ePreferred in body-in-white (BIW), interior trim, and cover assemblies\u003c\/li\u003e\n  \u003cli\u003eCompatible with thread-locking compounds and prevailing torque nuts for vibration resistance\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e② Serrated Flange (Toothed Flange)\u003c\/h3\u003e\n\u003cp\u003eFeatures radial serrations machined into the flange underside. Upon tightening, the teeth bite into the mating surface, creating a mechanical lock that resists vibration-induced loosening without any additional locking element.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIntegral serrated locking feature — no separate lock washer required\u003c\/li\u003e\n  \u003cli\u003eSuperior resistance to vibration and dynamic loosening\u003c\/li\u003e\n  \u003cli\u003eIdeal for powertrain, chassis, and battery enclosure joints subject to continuous vibration\u003c\/li\u003e\n  \u003cli\u003eWidely used in EV motor mounts, battery pack frames, and suspension brackets\u003c\/li\u003e\n  \u003cli\u003eNot recommended for soft or easily damaged mating surfaces\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eMaterial Options\u003c\/h2\u003e\n\n\u003ch3\u003eOption A — Alloy Steel 10B21 (Boron Steel)\u003c\/h3\u003e\n\u003cp\u003e10B21 is a boron-alloyed low-carbon steel widely used in automotive fastener manufacturing. The addition of boron significantly improves hardenability, allowing Class 8.8 mechanical properties to be achieved with lower alloy content and excellent cold-forging characteristics.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSuperior hardenability vs. plain carbon steel\u003c\/li\u003e\n  \u003cli\u003eExcellent cold-heading formability — ideal for high-volume production\u003c\/li\u003e\n  \u003cli\u003eConsistent mechanical properties across large production lots\u003c\/li\u003e\n  \u003cli\u003ePreferred material for automotive OEM and Tier-1 supply chains\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eOption B — Carbon Steel 35K\u003c\/h3\u003e\n\u003cp\u003e35K is a medium-carbon steel offering good strength and toughness at an economical cost. Suitable for Class 8.8 fasteners in general industrial and automotive applications where boron-alloyed steel is not specifically required.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eGood balance of strength and ductility\u003c\/li\u003e\n  \u003cli\u003eCost-effective for high-volume standard fastener applications\u003c\/li\u003e\n  \u003cli\u003eWidely available and well-understood in global supply chains\u003c\/li\u003e\n  \u003cli\u003eSuitable for non-critical structural joints and general assembly\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eMechanical Properties — Class 8.8\u003c\/h2\u003e\n\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eProperty\u003c\/th\u003e\n      \u003cth\u003eSpecification\u003c\/th\u003e\n      \u003cth\u003eStandard Reference\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eMaterial\u003c\/td\u003e\n      \u003ctd\u003eAlloy Steel 10B21 or Carbon Steel 35K\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eProperty Class\u003c\/td\u003e\n      \u003ctd\u003e8.8\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eNominal Tensile Strength (Rm)\u003c\/td\u003e\n      \u003ctd\u003e≥ 800 MPa\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eProof Load Stress (Sp)\u003c\/td\u003e\n      \u003ctd\u003e600 MPa\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYield Strength (Rp0.2)\u003c\/td\u003e\n      \u003ctd\u003e≥ 640 MPa\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHardness (Vickers)\u003c\/td\u003e\n      \u003ctd\u003e250 – 320 HV\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eCore Hardness (Rockwell)\u003c\/td\u003e\n      \u003ctd\u003e22 – 32 HRC\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eElongation after fracture\u003c\/td\u003e\n      \u003ctd\u003e≥ 12%\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 898-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eSurface Treatment\u003c\/td\u003e\n      \u003ctd\u003eZinc CR3 (trivalent chromate electroplate)\u003c\/td\u003e\n      \u003ctd\u003eDIN 267-11\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eCorrosion Resistance\u003c\/td\u003e\n      \u003ctd\u003e≥ 480 hours neutral salt spray (NSS)\u003c\/td\u003e\n      \u003ctd\u003eDIN 267-11 \/ ISO 9227\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDimensional Reference — DIN 6921 Key Parameters\u003c\/h2\u003e\n\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eThread Size\u003c\/th\u003e\n      \u003cth\u003ePitch (mm)\u003c\/th\u003e\n      \u003cth\u003eWidth Across Flats s (mm)\u003c\/th\u003e\n      \u003cth\u003eFlange Diameter dc (mm)\u003c\/th\u003e\n      \u003cth\u003eHead Height k (mm)\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM5\u003c\/td\u003e\n\u003ctd\u003e0.8\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003ctd\u003e14.2\u003c\/td\u003e\n\u003ctd\u003e3.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM6\u003c\/td\u003e\n\u003ctd\u003e1.0\u003c\/td\u003e\n\u003ctd\u003e10\u003c\/td\u003e\n\u003ctd\u003e17.0\u003c\/td\u003e\n\u003ctd\u003e4.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM8\u003c\/td\u003e\n\u003ctd\u003e1.25\u003c\/td\u003e\n\u003ctd\u003e13\u003c\/td\u003e\n\u003ctd\u003e22.0\u003c\/td\u003e\n\u003ctd\u003e5.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM10\u003c\/td\u003e\n\u003ctd\u003e1.5\u003c\/td\u003e\n\u003ctd\u003e15 \/ 16\u003c\/td\u003e\n\u003ctd\u003e27.0\u003c\/td\u003e\n\u003ctd\u003e6.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM12\u003c\/td\u003e\n\u003ctd\u003e1.75\u003c\/td\u003e\n\u003ctd\u003e18\u003c\/td\u003e\n\u003ctd\u003e32.0\u003c\/td\u003e\n\u003ctd\u003e8.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM14\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003ctd\u003e21\u003c\/td\u003e\n\u003ctd\u003e37.0\u003c\/td\u003e\n\u003ctd\u003e9.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM16\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003ctd\u003e24\u003c\/td\u003e\n\u003ctd\u003e43.0\u003c\/td\u003e\n\u003ctd\u003e10.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM20\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003ctd\u003e30\u003c\/td\u003e\n\u003ctd\u003e54.0\u003c\/td\u003e\n\u003ctd\u003e12.5\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eFull dimensional tables per DIN 6921. Custom lengths and thread pitches available upon request.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eSurface Treatment: Zinc CR3 (Trivalent Chromate)\u003c\/h2\u003e\n\u003cp\u003eThe Zinc CR3 finish applied to FULLERKREG DIN 6921 Class 8.8 bolts provides robust corrosion protection while meeting the strictest environmental compliance requirements for automotive supply chains. CR3 denotes trivalent chromium passivation — free of hexavalent chromium (Cr⁶⁺), fully compliant with RoHS, ELV Directive, and REACH regulations.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChromate Type:\u003c\/strong\u003e Trivalent chromate (Cr³⁺) — no hexavalent chromium (Cr⁶⁺)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAppearance:\u003c\/strong\u003e Bright silver \/ clear to light blue iridescent finish\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCorrosion Protection:\u003c\/strong\u003e ≥ 480 hours neutral salt spray (NSS) to first red rust\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoating Standard:\u003c\/strong\u003e DIN 267-11 \/ DIN EN ISO 4042\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRoHS Compliant:\u003c\/strong\u003e ✅ Yes — no restricted substances\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eELV Directive Compliant:\u003c\/strong\u003e ✅ Yes — suitable for automotive OEM supply\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHydrogen Embrittlement Relief:\u003c\/strong\u003e Controlled baking process post-plating per DIN EN ISO 4042 to eliminate embrittlement risk in Class 8.8 fasteners\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoating Thickness:\u003c\/strong\u003e Typically 5–12 µm (per DIN EN ISO 4042 tolerance class)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003ePrimary Application Sectors\u003c\/h2\u003e\n\n\u003ch3\u003e🔋 New Energy Vehicles (NEV \/ EV)\u003c\/h3\u003e\n\u003cp\u003eFULLERKREG DIN 6921 Class 8.8 Zinc CR3 bolts are engineered for the demanding fastening requirements of electric vehicle platforms:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eBattery pack enclosure panels and module frames\u003c\/li\u003e\n  \u003cli\u003eElectric motor and reducer housing assembly\u003c\/li\u003e\n  \u003cli\u003eHigh-voltage cable tray and busbar bracket fastening\u003c\/li\u003e\n  \u003cli\u003eThermal management system (TMS) — coolant plate and heat exchanger mounting\u003c\/li\u003e\n  \u003cli\u003eOnboard charger (OBC) and power distribution unit (PDU) enclosures\u003c\/li\u003e\n  \u003cli\u003eChassis cross-members and subframe structural joints\u003c\/li\u003e\n  \u003cli\u003eSeat rail and occupant safety system anchoring\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e🚗 Conventional Automotive \u0026amp; Commercial Vehicles\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eEngine peripheral components — timing covers, oil pans, valve covers\u003c\/li\u003e\n  \u003cli\u003eTransmission and gearbox housing assembly\u003c\/li\u003e\n  \u003cli\u003eSuspension components — control arms, stabilizer bar brackets, knuckles\u003c\/li\u003e\n  \u003cli\u003eBrake system — caliper mounting, disc shield, ABS sensor brackets\u003c\/li\u003e\n  \u003cli\u003eExhaust system heat shields and catalytic converter brackets\u003c\/li\u003e\n  \u003cli\u003eBody-in-white (BIW) structural joints and door hinge assemblies\u003c\/li\u003e\n  \u003cli\u003eInterior trim and dashboard bracket fastening\u003c\/li\u003e\n  \u003cli\u003eHVAC system and air conditioning compressor mounting\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy Choose FULLERKREG DIN 6921 Class 8.8?\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eAutomotive-Grade Manufacturing:\u003c\/strong\u003e Produced in Wuhu, Anhui — China's premier automotive manufacturing hub, co-located with Chery Automobile's global headquarters. Our facility operates within a mature automotive supply chain ecosystem with decades of fastener manufacturing expertise.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eDual Material Options:\u003c\/strong\u003e Choose between Alloy Steel 10B21 (boron steel, preferred for OEM supply) or Carbon Steel 35K (cost-effective for general applications) — both meeting Class 8.8 mechanical requirements.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eRoHS \u0026amp; ELV Compliant Finish:\u003c\/strong\u003e Zinc CR3 trivalent chromate coating meets EU automotive environmental directives — no hexavalent chromium, suitable for global OEM supply chains.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFull DIN Compliance:\u003c\/strong\u003e Every batch manufactured and inspected to DIN 6921, DIN EN ISO 898-1, and DIN 267-11 standards.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFull Traceability:\u003c\/strong\u003e Material certificates (MTC), mechanical test reports, salt spray test records, and coating inspection data available per shipment.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eBoth Flange Types Stocked:\u003c\/strong\u003e Non-serrated and serrated flange variants available across the full size range.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eHigh-Volume Capability:\u003c\/strong\u003e Consistent lot-to-lot quality suitable for OEM and Tier-1 supplier procurement programs.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFlexible Packaging:\u003c\/strong\u003e Bulk, box, and custom packaging options available to suit assembly line requirements.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eApplicable Standards \u0026amp; References\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDIN 6921\u003c\/strong\u003e — Hexagon bolts with flange (metric coarse thread)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDIN EN ISO 898-1\u003c\/strong\u003e — Mechanical properties of fasteners: bolts, screws and studs (property class 8.8)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDIN 267-11\u003c\/strong\u003e — Fasteners: technical delivery conditions — electroplated coatings\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDIN EN ISO 4042\u003c\/strong\u003e — Fasteners: electroplated coatings (coating thickness, hydrogen embrittlement relief)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eISO 9227\u003c\/strong\u003e — Corrosion tests in artificial atmospheres — neutral salt spray (NSS) test\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRoHS Directive 2011\/65\/EU\u003c\/strong\u003e — Restriction of hazardous substances\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eELV Directive 2000\/53\/EC\u003c\/strong\u003e — End-of-life vehicles (hexavalent chromium restriction)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eOrdering \u0026amp; Customization\u003c\/h2\u003e\n\u003cp\u003eFULLERKREG supplies DIN 6921 Class 8.8 Zinc CR3 bolts in standard and custom configurations. Please specify the following when placing an inquiry:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThread diameter and pitch (e.g., M8 × 1.25, M10 × 1.5)\u003c\/li\u003e\n  \u003cli\u003eNominal length (e.g., 20 mm, 35 mm, 50 mm)\u003c\/li\u003e\n  \u003cli\u003eFlange type: Non-Serrated or Serrated\u003c\/li\u003e\n  \u003cli\u003eMaterial preference: Alloy Steel 10B21 or Carbon Steel 35K\u003c\/li\u003e\n  \u003cli\u003eRequired quantity and packaging format (bulk \/ box \/ reel)\u003c\/li\u003e\n  \u003cli\u003eCertification requirements (PPAP, IATF 16949, material certificates, salt spray reports)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eContact our technical sales team for datasheets, samples, and volume pricing.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003cp\u003e\u003cem\u003eFULLERKREG — Precision Fasteners for the Automotive Future. Manufactured in Wuhu, China.\u003c\/em\u003e\u003c\/p\u003e","products":[],"url":"https:\/\/www.fullerkr.com\/collections\/din-6921-class-8-8-hex-flange-bolt-zinc-finish.oembed","provider":"Fullerkreg Fasteners","version":"1.0","type":"link"}