{"title":"DIN 603 Carriage Bolt 8.8 Zinc CR3","description":"\u003ch1\u003eDIN 603 Carriage Bolt — Grade 8.8 | Zinc CR3 | FULLERKREG\u003c\/h1\u003e\n\n\u003cp\u003eFULLERKREG DIN 603 Grade 8.8 Zinc CR3 Carriage Bolts are high-strength round-head square-neck bolts engineered for structural and load-bearing applications that demand greater clamping force than standard Grade 4.8 fasteners. Manufactured from Alloy Steel 10B21 (boron steel) or Carbon Steel 35K and finished with a RoHS-compliant Zinc CR3 (trivalent chromate) electroplated coating, these bolts combine the anti-rotation convenience of the classic DIN 603 carriage bolt design with the mechanical performance required for demanding structural, industrial, and heavy-duty assembly applications.\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 603\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCommon Name:\u003c\/strong\u003e High-Strength Carriage Bolt \/ Coach Bolt \/ Round Head Square Neck Bolt\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\u003eHead Type:\u003c\/strong\u003e Round (domed) head with square neck\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e FULLERKREG\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhat Is a DIN 603 Carriage Bolt?\u003c\/h2\u003e\n\u003cp\u003eThe DIN 603 carriage bolt — also known as a coach bolt or round head square neck bolt — is a specialized fastener defined by three key geometric features that make it uniquely suited to applications requiring single-sided assembly:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSmooth Domed Head:\u003c\/strong\u003e The low-profile, rounded head presents a clean, tamper-resistant appearance on the visible face of the joint. No drive recess is present — the bolt is tightened exclusively from the nut side, leaving a smooth, snag-free surface.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSquare Neck (Collar):\u003c\/strong\u003e Immediately below the head, a short square section embeds into the substrate (timber or a pre-punched square hole in metal) when the nut is tightened, preventing the bolt from rotating. This enables single-sided tightening with a wrench on the nut alone — no tool access required on the bolt head side.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThreaded Shank:\u003c\/strong\u003e The shank carries a metric coarse thread accepting a standard hex nut or flange nut. Shorter lengths may be fully threaded; longer lengths feature an unthreaded grip section.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eGrade 8.8 vs Grade 4.8:\u003c\/strong\u003e The Grade 8.8 variant delivers approximately double the tensile strength of the standard Grade 4.8 carriage bolt, making it the preferred choice for structural timber connections, heavy machinery, and load-bearing joints where higher clamping forces are required.\u003c\/p\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 that is the preferred material for high-volume automotive and structural fastener production. The addition of boron (typically 0.0005–0.003%) dramatically improves hardenability, allowing Grade 8.8 mechanical properties to be achieved with lower alloy content and excellent cold-forging characteristics.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCarbon Content:\u003c\/strong\u003e ~0.18–0.23% C\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBoron Addition:\u003c\/strong\u003e 0.0005–0.003% B — significantly improves hardenability\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSuperior hardenability\u003c\/strong\u003e vs plain carbon steel — consistent mechanical properties across large cross-sections\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eExcellent cold-heading formability\u003c\/strong\u003e — ideal for high-volume production with tight dimensional tolerances\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePreferred material\u003c\/strong\u003e for automotive OEM and Tier-1 structural fastener supply chains\u003c\/li\u003e\n  \u003cli\u003eConsistent mechanical properties across large production lots\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 a reliable balance of strength and toughness at an economical cost. Suitable for Grade 8.8 fasteners in general structural and industrial applications where boron-alloyed steel is not specifically required.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCarbon Content:\u003c\/strong\u003e ~0.32–0.39% C (medium carbon)\u003c\/li\u003e\n  \u003cli\u003eGood balance of tensile strength and ductility for Grade 8.8 requirements\u003c\/li\u003e\n  \u003cli\u003eCost-effective for high-volume standard structural 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 heavy-duty assembly\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eMechanical Properties — Grade 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 (NSS)\u003c\/td\u003e\n      \u003ctd\u003e72 – 120 hours neutral salt spray\u003c\/td\u003e\n      \u003ctd\u003eDIN 267-11 \/ ISO 9227\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eCoating Thickness\u003c\/td\u003e\n      \u003ctd\u003eTypically 5 – 12 µm\u003c\/td\u003e\n      \u003ctd\u003eDIN EN ISO 4042\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eGrade Comparison: 4.8 vs 8.8\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eProperty\u003c\/th\u003e\n      \u003cth\u003eGrade 4.8 (Standard)\u003c\/th\u003e\n      \u003cth\u003eGrade 8.8 (This Product)\u003c\/th\u003e\n      \u003cth\u003eImprovement\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eTensile Strength (Rm)\u003c\/td\u003e\n      \u003ctd\u003e≥ 420 MPa\u003c\/td\u003e\n      \u003ctd\u003e≥ 800 MPa\u003c\/td\u003e\n      \u003ctd\u003e+90%\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eYield Strength (Rp0.2)\u003c\/td\u003e\n      \u003ctd\u003e≥ 340 MPa\u003c\/td\u003e\n      \u003ctd\u003e≥ 640 MPa\u003c\/td\u003e\n      \u003ctd\u003e+88%\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eProof Load Stress (Sp)\u003c\/td\u003e\n      \u003ctd\u003e310 MPa\u003c\/td\u003e\n      \u003ctd\u003e600 MPa\u003c\/td\u003e\n      \u003ctd\u003e+94%\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHardness\u003c\/td\u003e\n      \u003ctd\u003e130 – 220 HV\u003c\/td\u003e\n      \u003ctd\u003e250 – 320 HV\u003c\/td\u003e\n      \u003ctd\u003eHigher\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eMaterial\u003c\/td\u003e\n      \u003ctd\u003eLow Carbon Steel Q195\u003c\/td\u003e\n      \u003ctd\u003eAlloy Steel 10B21 \/ Carbon Steel 35K\u003c\/td\u003e\n      \u003ctd\u003eHigher alloy\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eTypical Use\u003c\/td\u003e\n      \u003ctd\u003eLight structural, timber, furniture\u003c\/td\u003e\n      \u003ctd\u003eHeavy structural, machinery, load-bearing\u003c\/td\u003e\n      \u003ctd\u003e—\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eSurface Treatment: Zinc CR3 (Trivalent Chromate)\u003c\/h2\u003e\n\u003cp\u003eFULLERKREG DIN 603 Grade 8.8 carriage bolts are finished with a Zinc CR3 electroplated coating — the industry standard for RoHS-compliant corrosion protection on high-strength carbon and alloy steel fasteners.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChromate Type:\u003c\/strong\u003e Trivalent chromate (Cr³⁺) — zero 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 72 – 120 hours neutral salt spray (NSS) to first red rust (per ISO 9227)\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\u003eCoating Thickness:\u003c\/strong\u003e Typically 5 – 12 µm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRoHS Compliant:\u003c\/strong\u003e ✅ Yes — no restricted hazardous substances\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eELV Directive Compliant:\u003c\/strong\u003e ✅ Yes — suitable for automotive and industrial supply chains\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eREACH Compliant:\u003c\/strong\u003e ✅ Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHydrogen Embrittlement Relief:\u003c\/strong\u003e Controlled baking process post-plating per DIN EN ISO 4042 — critical for Grade 8.8 high-strength fasteners to eliminate embrittlement risk\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cblockquote\u003e\n  \u003cp\u003e\u003cstrong\u003e⚠️ Important — Hydrogen Embrittlement:\u003c\/strong\u003e Grade 8.8 fasteners with hardness ≥ 320 HV are susceptible to hydrogen embrittlement during electroplating. FULLERKREG applies a controlled post-plating baking process (typically 200°C for ≥ 4 hours) per DIN EN ISO 4042 to eliminate absorbed hydrogen and ensure the mechanical integrity of every Grade 8.8 bolt.\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDimensional Reference — DIN 603 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\u003eHead Diameter dk (mm)\u003c\/th\u003e\n      \u003cth\u003eHead Height k (mm)\u003c\/th\u003e\n      \u003cth\u003eSquare Neck Width f (mm)\u003c\/th\u003e\n      \u003cth\u003eSquare Neck Height m (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\u003e14.0\u003c\/td\u003e\n\u003ctd\u003e3.0\u003c\/td\u003e\n\u003ctd\u003e5.0\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\u003e16.0\u003c\/td\u003e\n\u003ctd\u003e3.6\u003c\/td\u003e\n\u003ctd\u003e6.0\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\u003e21.0\u003c\/td\u003e\n\u003ctd\u003e4.8\u003c\/td\u003e\n\u003ctd\u003e8.0\u003c\/td\u003e\n\u003ctd\u003e5.0\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\u003e26.0\u003c\/td\u003e\n\u003ctd\u003e6.0\u003c\/td\u003e\n\u003ctd\u003e10.0\u003c\/td\u003e\n\u003ctd\u003e6.0\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\u003e30.0\u003c\/td\u003e\n\u003ctd\u003e7.2\u003c\/td\u003e\n\u003ctd\u003e12.0\u003c\/td\u003e\n\u003ctd\u003e7.0\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\u003e35.0\u003c\/td\u003e\n\u003ctd\u003e8.4\u003c\/td\u003e\n\u003ctd\u003e14.0\u003c\/td\u003e\n\u003ctd\u003e8.0\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\u003e40.0\u003c\/td\u003e\n\u003ctd\u003e9.6\u003c\/td\u003e\n\u003ctd\u003e16.0\u003c\/td\u003e\n\u003ctd\u003e9.0\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\u003e50.0\u003c\/td\u003e\n\u003ctd\u003e12.0\u003c\/td\u003e\n\u003ctd\u003e20.0\u003c\/td\u003e\n\u003ctd\u003e11.0\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eStandard lengths range from 20 mm to 300 mm depending on thread size. Full dimensional tables per DIN 603. Custom lengths available upon request.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eTypical Application Sectors\u003c\/h2\u003e\n\n\u003ch3\u003e🏗️ Heavy Structural Timber \u0026amp; Construction\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eHeavy timber frame and post-and-beam structural connections requiring high clamping force\u003c\/li\u003e\n  \u003cli\u003eGlulam beam, LVL, and engineered timber (CLT) structural joints\u003c\/li\u003e\n  \u003cli\u003eTimber bridge decking and heavy boardwalk structural fastening\u003c\/li\u003e\n  \u003cli\u003eRetaining wall timber crib connections under high lateral load\u003c\/li\u003e\n  \u003cli\u003eScaffold and falsework structural joints requiring certified load capacity\u003c\/li\u003e\n  \u003cli\u003ePrefabricated timber building module connections\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e⚙️ Industrial Machinery \u0026amp; Equipment\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eHeavy machinery base plate and frame fastening\u003c\/li\u003e\n  \u003cli\u003eConveyor system structural connections and drive unit mounting\u003c\/li\u003e\n  \u003cli\u003eMaterial handling equipment — crane, hoist, and lifting frame fastening\u003c\/li\u003e\n  \u003cli\u003eCompressor, pump, and motor base fastening\u003c\/li\u003e\n  \u003cli\u003eIndustrial press and stamping machine structural connections\u003c\/li\u003e\n  \u003cli\u003eMining and quarrying equipment structural fastening\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e🚚 Transportation \u0026amp; Vehicle Structures\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eTruck body and trailer structural connections\u003c\/li\u003e\n  \u003cli\u003eBus and coach body frame fastening\u003c\/li\u003e\n  \u003cli\u003eRailway wagon and rolling stock structural joints\u003c\/li\u003e\n  \u003cli\u003eAgricultural machinery and implement structural fastening\u003c\/li\u003e\n  \u003cli\u003eConstruction vehicle cab and body structural connections\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e🌳 Outdoor \u0026amp; Infrastructure Structures\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eHeavy-duty playground and recreational equipment structural fastening\u003c\/li\u003e\n  \u003cli\u003eSports facility bleacher and grandstand structural connections\u003c\/li\u003e\n  \u003cli\u003eHighway noise barrier and crash barrier structural joints\u003c\/li\u003e\n  \u003cli\u003eUtility pole and transmission tower base connections\u003c\/li\u003e\n  \u003cli\u003eSolar panel mounting structure heavy-duty connections\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eKey Features \u0026amp; Design Advantages\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e💪 \u003cstrong\u003eHigh-Strength Grade 8.8:\u003c\/strong\u003e Tensile strength ≥ 800 MPa — approximately double the strength of standard Grade 4.8 carriage bolts. Suitable for load-bearing structural joints where higher clamping forces are required.\u003c\/li\u003e\n  \u003cli\u003e🔒 \u003cstrong\u003eAnti-Rotation Square Neck:\u003c\/strong\u003e The square collar embeds into timber or a pre-punched square hole, preventing bolt rotation during nut tightening — enabling single-sided assembly with no tool access required on the bolt head side.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eDual Material Options:\u003c\/strong\u003e Choose between Alloy Steel 10B21 (boron steel, preferred for OEM and high-volume structural supply) or Carbon Steel 35K (cost-effective for general structural applications) — both meeting Grade 8.8 mechanical requirements.\u003c\/li\u003e\n  \u003cli\u003e🛡️ \u003cstrong\u003eRoHS-Compliant Zinc CR3 Finish:\u003c\/strong\u003e Trivalent chromate coating — no hexavalent chromium — meets EU environmental directives for global supply chains.\u003c\/li\u003e\n  \u003cli\u003e⚠️ \u003cstrong\u003eHydrogen Embrittlement Controlled:\u003c\/strong\u003e Post-plating baking process per DIN EN ISO 4042 eliminates hydrogen embrittlement risk — critical for Grade 8.8 high-strength fasteners.\u003c\/li\u003e\n  \u003cli\u003e📏 \u003cstrong\u003eTamper-Resistant Smooth Head:\u003c\/strong\u003e The domed head has no drive recess, providing a clean appearance and resistance to unauthorized removal without nut-side access.\u003c\/li\u003e\n  \u003cli\u003e📊 \u003cstrong\u003eFull Traceability:\u003c\/strong\u003e Material certificates, mechanical test reports, hardness test records, and coating inspection data available per shipment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVerify substrate compatibility:\u003c\/strong\u003e Grade 8.8 carriage bolts generate significantly higher clamping forces than Grade 4.8. Ensure the substrate (timber species, metal thickness, or composite material) is rated for the increased bearing stress at the bolt head and nut contact areas.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrepare the substrate:\u003c\/strong\u003e Drill a clearance hole equal to the bolt diameter. For timber, the square neck will self-embed; for metal, punch or drill a square hole matching the neck dimensions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInsert the bolt:\u003c\/strong\u003e Push the carriage bolt through the hole from the front (visible) face.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEmbed the square neck:\u003c\/strong\u003e Tap the bolt head firmly with a mallet to seat the square neck fully into the timber or square hole. Grade 8.8 bolts require firm seating to prevent rotation under higher tightening torques.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApply washer and nut:\u003c\/strong\u003e Place a hardened flat washer (Grade 8 or equivalent) and Grade 8 hex nut on the threaded end. Use a washer under the nut to distribute the higher clamping load and prevent pull-through or surface damage.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTighten from the nut side:\u003c\/strong\u003e Use a calibrated torque wrench to tighten to the recommended torque for Grade 8.8 and the thread size. Do not exceed the maximum torque — Grade 8.8 fasteners are susceptible to torsional fracture if overtightened.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eRecommended Tightening Torque — Grade 8.8\u003c\/h2\u003e\n\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eThread Size\u003c\/th\u003e\n      \u003cth\u003eTightening Torque (Nm) — Dry\u003c\/th\u003e\n      \u003cth\u003eTightening Torque (Nm) — Lubricated\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\u003e6.0\u003c\/td\u003e\n\u003ctd\u003e4.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM6\u003c\/td\u003e\n\u003ctd\u003e10.4\u003c\/td\u003e\n\u003ctd\u003e7.8\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM8\u003c\/td\u003e\n\u003ctd\u003e25\u003c\/td\u003e\n\u003ctd\u003e19\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM10\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e38\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM12\u003c\/td\u003e\n\u003ctd\u003e87\u003c\/td\u003e\n\u003ctd\u003e65\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM14\u003c\/td\u003e\n\u003ctd\u003e138\u003c\/td\u003e\n\u003ctd\u003e104\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM16\u003c\/td\u003e\n\u003ctd\u003e213\u003c\/td\u003e\n\u003ctd\u003e160\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM20\u003c\/td\u003e\n\u003ctd\u003e415\u003c\/td\u003e\n\u003ctd\u003e311\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eTorque values are indicative for Grade 8.8 bolts at 70% proof load. Use a calibrated torque wrench for structural applications. Always verify with your structural engineer for safety-critical joints.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy Choose FULLERKREG DIN 603 Grade 8.8 Zinc CR3?\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFull DIN 603 \u0026amp; ISO 898-1 Compliance:\u003c\/strong\u003e Every batch manufactured to DIN 603 dimensional standards and DIN EN ISO 898-1 Grade 8.8 mechanical requirements.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eHydrogen Embrittlement Controlled:\u003c\/strong\u003e Post-plating baking process per DIN EN ISO 4042 — essential for Grade 8.8 electroplated fasteners.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eDual Material Options:\u003c\/strong\u003e Alloy Steel 10B21 or Carbon Steel 35K — both meeting Grade 8.8 requirements, selectable based on application and procurement preference.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eRoHS \u0026amp; ELV Compliant Zinc CR3 Finish:\u003c\/strong\u003e Trivalent chromate coating — no hexavalent chromium — meets EU environmental directives.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFull Traceability:\u003c\/strong\u003e Material certificates (MTC), mechanical test reports, hardness records, and salt spray test data available per shipment.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eHigh-Volume Production Capability:\u003c\/strong\u003e Consistent lot-to-lot quality for structural, industrial, and transportation procurement programs.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eWide Size Range:\u003c\/strong\u003e M5 through M20, lengths from 20 mm to 300 mm.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFlexible Packaging:\u003c\/strong\u003e Bulk, box, and custom packaging options available.\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 603\u003c\/strong\u003e — Round head square neck bolts (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 603 Grade 8.8 Zinc CR3 carriage 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., M10 × 1.5, M12 × 1.75)\u003c\/li\u003e\n  \u003cli\u003eNominal length (e.g., 40 mm, 80 mm, 150 mm)\u003c\/li\u003e\n  \u003cli\u003eFully threaded or partially threaded shank preference\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 \/ pallet)\u003c\/li\u003e\n  \u003cli\u003eCertification requirements (PPAP, material certificates, mechanical test reports, hardness records, hydrogen embrittlement relief baking records)\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 — High-Strength Fasteners for Structural and Industrial Excellence.\u003c\/em\u003e\u003c\/p\u003e","products":[],"url":"https:\/\/www.fullerkr.com\/collections\/din-603-carriage-bolt-8-8-zinc-cr3.oembed","provider":"Fullerkreg Fasteners","version":"1.0","type":"link"}