{"title":"Carriage Bolts (DIN 603) - Marine Stainless Steel (A4)","description":"\u003ch1\u003eDIN 603 Carriage Bolt — Marine Stainless Steel A4 (SUS316) | Grade A4-70 | FULLERKREG\u003c\/h1\u003e\n\n\u003cp\u003eFULLERKREG DIN 603 Marine Stainless Steel A4 Carriage Bolts represent the highest level of corrosion resistance available in the DIN 603 carriage bolt range. Manufactured from A4 austenitic stainless steel (SUS316 \/ 1.4401), these bolts incorporate molybdenum into the alloy composition — the critical element that provides superior resistance to chloride-induced pitting and crevice corrosion that limits the performance of standard A2 (SUS304) stainless steel. Finished with acid washing and passivation, they deliver a bright, clean surface and maximum passive layer integrity for the most demanding marine, coastal, chemical, and industrial environments.\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 Marine Carriage Bolt \/ Coach Bolt \/ Round Head Square Neck Bolt\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e A4 Marine Stainless Steel (SUS316 \/ 1.4401)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProperty Class \/ Grade:\u003c\/strong\u003e A4-70 (per ISO 3506-1)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSurface Finish:\u003c\/strong\u003e Acid Washed + Passivated\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:\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 ideal for marine and outdoor environments.\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 timber substrate or a pre-punched square hole when the nut is tightened, preventing the bolt from rotating. This enables single-sided tightening with a wrench on the nut alone — critical in marine applications where access is often restricted.\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\n\u003chr\u003e\n\n\u003ch2\u003eMaterial: A4 Marine Stainless Steel (SUS316 \/ 1.4401)\u003c\/h2\u003e\n\u003cp\u003eA4 stainless steel — designated SUS316 in JIS, 1.4401 in EN, and commonly known as marine-grade or 316 stainless steel — is the premier choice for fasteners in corrosive, chloride-rich, and chemically aggressive environments. The key differentiator from A2 (SUS304) is the addition of \u003cstrong\u003e2–3% molybdenum (Mo)\u003c\/strong\u003e, which dramatically improves resistance to pitting and crevice corrosion in chloride environments such as seawater, coastal salt spray, de-icing salts, and chemical processing media.\u003c\/p\u003e\n\n\u003ch3\u003eChemical Composition (Typical)\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eElement\u003c\/th\u003e\n      \u003cth\u003eA4 \/ SUS316 Content (%)\u003c\/th\u003e\n      \u003cth\u003eA2 \/ SUS304 Content (%)\u003c\/th\u003e\n      \u003cth\u003eKey Difference\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eChromium (Cr)\u003c\/td\u003e\n\u003ctd\u003e16.5 – 18.5\u003c\/td\u003e\n\u003ctd\u003e17.5 – 19.5\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eNickel (Ni)\u003c\/td\u003e\n\u003ctd\u003e10.0 – 13.0\u003c\/td\u003e\n\u003ctd\u003e8.0 – 10.5\u003c\/td\u003e\n\u003ctd\u003eHigher Ni in A4\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMolybdenum (Mo)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003e2.0 – 3.0\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eNone\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003e⭐ Critical for chloride resistance\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCarbon (C)\u003c\/td\u003e\n\u003ctd\u003e≤ 0.07\u003c\/td\u003e\n\u003ctd\u003e≤ 0.07\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eManganese (Mn)\u003c\/td\u003e\n\u003ctd\u003e≤ 2.0\u003c\/td\u003e\n\u003ctd\u003e≤ 2.0\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSilicon (Si)\u003c\/td\u003e\n\u003ctd\u003e≤ 1.0\u003c\/td\u003e\n\u003ctd\u003e≤ 1.0\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eIron (Fe)\u003c\/td\u003e\n\u003ctd\u003eBalance\u003c\/td\u003e\n\u003ctd\u003eBalance\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eKey Material Properties\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChloride Resistance:\u003c\/strong\u003e Excellent — molybdenum content provides superior resistance to pitting and crevice corrosion in seawater, coastal salt spray, and chloride-containing chemical environments\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePassive Layer:\u003c\/strong\u003e Self-repairing chromium oxide (Cr₂O₃) passive layer — regenerates automatically when damaged in the presence of oxygen\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNon-Magnetic:\u003c\/strong\u003e Austenitic structure — non-magnetic in the annealed condition\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHygienic:\u003c\/strong\u003e Smooth, non-porous surface — suitable for food, pharmaceutical, and chemical processing environments\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTemperature Range:\u003c\/strong\u003e Suitable for continuous service from −196°C to +800°C (intermittent)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeldability:\u003c\/strong\u003e Excellent — all standard welding methods applicable; low carbon content minimizes sensitization risk\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRecycling:\u003c\/strong\u003e 100% recyclable — environmentally responsible material choice\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePREN (Pitting Resistance Equivalent Number):\u003c\/strong\u003e ~25–28 (vs ~18–20 for A2) — significantly higher pitting resistance\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eMechanical Properties — Grade A4-70\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\u003eA4 Stainless Steel (SUS316 \/ 1.4401)\u003c\/td\u003e\n      \u003ctd\u003eISO 3506-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eProperty Class\u003c\/td\u003e\n      \u003ctd\u003eA4-70\u003c\/td\u003e\n      \u003ctd\u003eISO 3506-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eMinimum Tensile Strength (Rm)\u003c\/td\u003e\n      \u003ctd\u003e≥ 700 MPa\u003c\/td\u003e\n      \u003ctd\u003eISO 3506-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e0.2% Proof Stress (Rp0.2)\u003c\/td\u003e\n      \u003ctd\u003e≥ 450 MPa\u003c\/td\u003e\n      \u003ctd\u003eISO 3506-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eElongation after fracture\u003c\/td\u003e\n      \u003ctd\u003e≥ 20%\u003c\/td\u003e\n      \u003ctd\u003eISO 3506-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHardness (Vickers, max)\u003c\/td\u003e\n      \u003ctd\u003e≤ 250 HV\u003c\/td\u003e\n      \u003ctd\u003eISO 3506-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eSurface Finish\u003c\/td\u003e\n      \u003ctd\u003eAcid Washed + Passivated\u003c\/td\u003e\n      \u003ctd\u003eASTM A967 \/ EN 2516\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eCorrosion Resistance\u003c\/td\u003e\n      \u003ctd\u003eInherent — self-repairing passive layer; superior chloride resistance vs A2\u003c\/td\u003e\n      \u003ctd\u003eISO 3506-1\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eSurface Finish: Acid Washing + Passivation\u003c\/h2\u003e\n\u003cp\u003eFULLERKREG A4 stainless steel DIN 603 carriage bolts are finished with a two-stage acid washing and passivation process that maximizes the inherent corrosion resistance of the SUS316 alloy.\u003c\/p\u003e\n\n\u003ch3\u003eStage 1 — Acid Washing (Pickling)\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eRemoves heat tint, scale, and oxide discoloration from the manufacturing and cold-heading process\u003c\/li\u003e\n  \u003cli\u003eDissolves free iron contamination on the surface that could initiate rust spots\u003c\/li\u003e\n  \u003cli\u003eRestores a uniform, bright, clean stainless steel surface across the entire batch\u003c\/li\u003e\n  \u003cli\u003eExposes a fresh, chromium- and molybdenum-rich surface layer ready for passivation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eStage 2 — Passivation\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eAccelerates and thickens the natural chromium oxide (Cr₂O₃) passive layer\u003c\/li\u003e\n  \u003cli\u003eMaximizes the corrosion resistance of the A4 stainless steel, particularly in chloride environments\u003c\/li\u003e\n  \u003cli\u003eRemoves any remaining free iron or contaminants\u003c\/li\u003e\n  \u003cli\u003eProduces a consistent, bright, silver-white appearance across the entire batch\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eResult\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAppearance:\u003c\/strong\u003e Bright, uniform silver-white — clean and aesthetically superior\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNo Coating Thickness:\u003c\/strong\u003e Zero added coating — thread dimensions remain at nominal tolerance, standard nuts fit without modification\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSelf-Repairing:\u003c\/strong\u003e Passive layer regenerates automatically in the presence of oxygen\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNo Peeling or Flaking:\u003c\/strong\u003e No applied layer to chip, peel, or wear away\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFood \u0026amp; Chemical Safe:\u003c\/strong\u003e Passivated A4 stainless steel is suitable for food contact and chemical processing environments\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eA4 vs A2: Why Molybdenum Makes the Difference\u003c\/h2\u003e\n\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eProperty\u003c\/th\u003e\n      \u003cth\u003eA4 (SUS316) — This Product\u003c\/th\u003e\n      \u003cth\u003eA2 (SUS304)\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eMolybdenum Content\u003c\/td\u003e\n      \u003ctd\u003e2.0 – 3.0%\u003c\/td\u003e\n      \u003ctd\u003eNone\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003ePREN (Pitting Resistance)\u003c\/td\u003e\n      \u003ctd\u003e~25 – 28\u003c\/td\u003e\n      \u003ctd\u003e~18 – 20\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eSeawater Resistance\u003c\/td\u003e\n      \u003ctd\u003e✅ Excellent — suitable for splash zone \u0026amp; immersion\u003c\/td\u003e\n      \u003ctd\u003e⚠️ Limited — pitting risk in seawater\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eCoastal Salt Spray\u003c\/td\u003e\n      \u003ctd\u003e✅ Excellent — suitable for direct coastal exposure\u003c\/td\u003e\n      \u003ctd\u003e⚠️ Moderate — may pit in heavy salt spray\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eDe-icing Salt Exposure\u003c\/td\u003e\n      \u003ctd\u003e✅ Suitable\u003c\/td\u003e\n      \u003ctd\u003e⚠️ Risk of pitting\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eChemical Processing\u003c\/td\u003e\n      \u003ctd\u003e✅ Suitable for many acids and chlorides\u003c\/td\u003e\n      \u003ctd\u003e⚠️ Limited chemical resistance\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eSwimming Pool Environments\u003c\/td\u003e\n      \u003ctd\u003e✅ Suitable (chlorinated water)\u003c\/td\u003e\n      \u003ctd\u003e⚠️ Not recommended\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eFood \u0026amp; Pharmaceutical\u003c\/td\u003e\n      \u003ctd\u003e✅ Preferred grade\u003c\/td\u003e\n      \u003ctd\u003e✅ Suitable\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eTensile Strength (A4-70 \/ A2-70)\u003c\/td\u003e\n      \u003ctd\u003e≥ 700 MPa\u003c\/td\u003e\n      \u003ctd\u003e≥ 700 MPa\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003ePrice\u003c\/td\u003e\n      \u003ctd\u003eHigher (Mo content)\u003c\/td\u003e\n      \u003ctd\u003eLower\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eCorrosion Resistance Comparison — All Finishes\u003c\/h2\u003e\n\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eFinish \/ Material\u003c\/th\u003e\n      \u003cth\u003eChloride Resistance\u003c\/th\u003e\n      \u003cth\u003eSalt Spray (NSS)\u003c\/th\u003e\n      \u003cth\u003eOutdoor Service Life\u003c\/th\u003e\n      \u003cth\u003eMarine Suitability\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eA4 Stainless (This Product)\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e⭐⭐⭐⭐⭐ Excellent\u003c\/td\u003e\n      \u003ctd\u003e≥ 1,000 hours\u003c\/td\u003e\n      \u003ctd\u003e30–50+ years\u003c\/td\u003e\n      \u003ctd\u003e✅ Yes — seawater \u0026amp; coastal\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eA2 Stainless (SUS304)\u003c\/td\u003e\n      \u003ctd\u003e⭐⭐⭐ Good (non-marine)\u003c\/td\u003e\n      \u003ctd\u003e≥ 500 hours\u003c\/td\u003e\n      \u003ctd\u003e20–50 years (non-coastal)\u003c\/td\u003e\n      \u003ctd\u003e⚠️ Splash zone only\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHot Dip Galvanized\u003c\/td\u003e\n      \u003ctd\u003e⭐⭐ Moderate\u003c\/td\u003e\n      \u003ctd\u003e≥ 1,000 hours\u003c\/td\u003e\n      \u003ctd\u003e20–50 years (structural)\u003c\/td\u003e\n      \u003ctd\u003e⚠️ Not for seawater immersion\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eZinc CR3 Electroplate\u003c\/td\u003e\n      \u003ctd\u003e⭐ Poor\u003c\/td\u003e\n      \u003ctd\u003e24 – 48 hours\u003c\/td\u003e\n      \u003ctd\u003e2 – 5 years (exposed)\u003c\/td\u003e\n      \u003ctd\u003e❌ No\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 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 16 mm to 200 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⛵ Marine \u0026amp; Boating\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eBoat deck hardware, cleats, and fitting fastening\u003c\/li\u003e\n  \u003cli\u003eTeak deck and timber deck planking fastening\u003c\/li\u003e\n  \u003cli\u003ePontoon, jetty, and floating dock timber connections\u003c\/li\u003e\n  \u003cli\u003eMast, boom, and rigging hardware structural fastening\u003c\/li\u003e\n  \u003cli\u003eMarine trailer and launching ramp structural connections\u003c\/li\u003e\n  \u003cli\u003eUnderwater and splash zone structural fastening (hull fittings, keel bolts)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e🌊 Coastal \u0026amp; Offshore Infrastructure\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eCoastal boardwalk and promenade timber decking\u003c\/li\u003e\n  \u003cli\u003eSea wall, breakwater, and coastal defence structure fastening\u003c\/li\u003e\n  \u003cli\u003eOffshore platform and jetty structural connections\u003c\/li\u003e\n  \u003cli\u003eCoastal signage, lighting, and street furniture fastening\u003c\/li\u003e\n  \u003cli\u003eTidal zone and splash zone structural timber connections\u003c\/li\u003e\n  \u003cli\u003eDesalination plant and water treatment facility fastening\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e🏊 Swimming Pools \u0026amp; Aquatic Facilities\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eSwimming pool surround and deck structural fastening\u003c\/li\u003e\n  \u003cli\u003ePool ladder, handrail, and diving board structural connections\u003c\/li\u003e\n  \u003cli\u003eAquatic centre and water park structure fastening\u003c\/li\u003e\n  \u003cli\u003eSpa, hot tub, and hydrotherapy pool equipment fastening\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e🧪 Chemical \u0026amp; Industrial Processing\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eChemical plant structural fastening in chloride-containing environments\u003c\/li\u003e\n  \u003cli\u003ePulp and paper mill equipment connections\u003c\/li\u003e\n  \u003cli\u003ePharmaceutical and bioprocessing facility structural fastening\u003c\/li\u003e\n  \u003cli\u003eFood and beverage processing plant — wash-down and high-humidity areas\u003c\/li\u003e\n  \u003cli\u003eWastewater treatment plant structural connections\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e🌿 Outdoor \u0026amp; Architectural (Coastal Zones)\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eCoastal residential and commercial building structural timber connections\u003c\/li\u003e\n  \u003cli\u003eBeachfront and waterfront development fastening\u003c\/li\u003e\n  \u003cli\u003eOutdoor furniture and structures within 1 km of the coastline\u003c\/li\u003e\n  \u003cli\u003eBridge and pedestrian walkway structural connections in coastal environments\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\u003eSuperior Chloride \u0026amp; Marine Corrosion Resistance:\u003c\/strong\u003e The 2–3% molybdenum content in A4 (SUS316) provides dramatically better resistance to pitting and crevice corrosion in seawater, coastal salt spray, and chloride-containing environments compared to standard A2 (SUS304).\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, critical in marine environments where access is often restricted.\u003c\/li\u003e\n  \u003cli\u003e✨ \u003cstrong\u003eBright, Aesthetic Finish:\u003c\/strong\u003e Acid washing and passivation produce a uniform, bright silver-white surface — ideal for visible marine hardware and architectural applications.\u003c\/li\u003e\n  \u003cli\u003e♻️ \u003cstrong\u003eNo Coating — No Compromise:\u003c\/strong\u003e Inherent stainless steel corrosion resistance — no zinc, chromate, or paint coating to chip, peel, or fail in harsh marine environments.\u003c\/li\u003e\n  \u003cli\u003e🧪 \u003cstrong\u003eNon-Magnetic:\u003c\/strong\u003e Austenitic A4 stainless steel is non-magnetic in the annealed condition — suitable for applications sensitive to magnetic interference.\u003c\/li\u003e\n  \u003cli\u003e🌡️ \u003cstrong\u003eWide Temperature Range:\u003c\/strong\u003e Suitable from cryogenic temperatures (−196°C) to elevated service temperatures (+800°C intermittent).\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eStandard Thread Fit:\u003c\/strong\u003e No coating thickness — standard-tolerance A4 nuts fit without modification.\u003c\/li\u003e\n  \u003cli\u003e🍽️ \u003cstrong\u003eFood \u0026amp; Chemical Safe:\u003c\/strong\u003e Passivated A4 stainless steel is the preferred grade for food processing, pharmaceutical, and chemical environments.\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\u003eLubricate the thread:\u003c\/strong\u003e Apply an anti-galling lubricant (molybdenum disulfide paste, PTFE tape, or anti-seize compound) to the thread before assembly. Stainless steel fasteners are prone to galling — lubrication is essential, especially in marine environments where fasteners may be tightened under difficult conditions.\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 lightly with a mallet to seat the square neck fully into the timber or square hole.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApply washer and nut:\u003c\/strong\u003e Always use A4 stainless steel flat washer and hex nut to maintain material compatibility. Never mix A4 bolts with carbon steel or A2 nuts in marine environments — galvanic corrosion may occur at the contact interface.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTighten from the nut side:\u003c\/strong\u003e Tighten slowly with a wrench — avoid impact tools or high-speed tightening to minimize galling risk. Tighten to the recommended torque for A4-70 and the thread size.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePeriodic Inspection:\u003c\/strong\u003e In marine environments, inspect fasteners periodically for signs of crevice corrosion at the joint interface, particularly in timber connections where moisture can be trapped.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eRecommended Tightening Torque — A4-70\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\u003e4.0\u003c\/td\u003e\n\u003ctd\u003e3.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM6\u003c\/td\u003e\n\u003ctd\u003e6.8\u003c\/td\u003e\n\u003ctd\u003e5.1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM8\u003c\/td\u003e\n\u003ctd\u003e16.5\u003c\/td\u003e\n\u003ctd\u003e12.4\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM10\u003c\/td\u003e\n\u003ctd\u003e33\u003c\/td\u003e\n\u003ctd\u003e25\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM12\u003c\/td\u003e\n\u003ctd\u003e57\u003c\/td\u003e\n\u003ctd\u003e43\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM14\u003c\/td\u003e\n\u003ctd\u003e90\u003c\/td\u003e\n\u003ctd\u003e68\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM16\u003c\/td\u003e\n\u003ctd\u003e140\u003c\/td\u003e\n\u003ctd\u003e105\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM20\u003c\/td\u003e\n\u003ctd\u003e272\u003c\/td\u003e\n\u003ctd\u003e204\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eTorque values are indicative for A4-70 bolts at 70% proof load. Always lubricate stainless steel threads before tightening to prevent galling. Verify with your structural or marine engineer for safety-critical applications.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy Choose FULLERKREG A4 Marine Stainless DIN 603 Carriage Bolts?\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFull DIN 603 \u0026amp; ISO 3506-1 Compliance:\u003c\/strong\u003e Every batch manufactured to DIN 603 dimensional standards and ISO 3506-1 A4-70 mechanical requirements.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eGenuine A4 \/ SUS316 Material:\u003c\/strong\u003e Full material traceability with chemical composition certificates confirming molybdenum content — not A2 misrepresented as A4.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eAcid Washed \u0026amp; Passivated:\u003c\/strong\u003e Superior surface finish maximizes the inherent corrosion resistance of A4 stainless steel — bright, clean, and consistent across every batch.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFull Traceability:\u003c\/strong\u003e Material certificates (MTC), mechanical test reports, and chemical composition reports (confirming Mo content) available per shipment.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eWide Size Range:\u003c\/strong\u003e M5 through M20, lengths from 16 mm to 200 mm — covering the full DIN 603 range in marine stainless steel.\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eMatched A4 Nuts \u0026amp; Washers Available:\u003c\/strong\u003e Complete A4 stainless steel fastener sets (bolt + nut + washer) available for simplified procurement and guaranteed material compatibility.\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\u003eISO 3506-1\u003c\/strong\u003e — Mechanical properties of corrosion-resistant stainless steel fasteners: bolts, screws and studs (A4-70)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEN 10088-1\u003c\/strong\u003e — Stainless steels — list of stainless steels (1.4401 \/ A4)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eASTM A967 \/ ASTM A380\u003c\/strong\u003e — Standard practice for passivation of stainless steel parts\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\u003eJIS G4303\u003c\/strong\u003e — Stainless steel bars (SUS316 material standard)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNORSOK M-630\u003c\/strong\u003e — Material data sheets for piping (referenced for offshore\/marine material selection)\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 A4-70 marine stainless steel 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., M8 × 1.25, M12 × 1.75)\u003c\/li\u003e\n  \u003cli\u003eNominal length (e.g., 30 mm, 60 mm, 100 mm)\u003c\/li\u003e\n  \u003cli\u003eFully threaded or partially threaded shank preference\u003c\/li\u003e\n  \u003cli\u003eWhether matched A4 nuts and washers are required\u003c\/li\u003e\n  \u003cli\u003eRequired quantity and packaging format (bulk \/ box \/ pallet)\u003c\/li\u003e\n  \u003cli\u003eCertification requirements (material certificates with Mo content confirmation, mechanical test reports, chemical composition 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 — Marine-Grade Fasteners for the World’s Most Demanding Environments. A4 Stainless Steel — Where Corrosion Cannot Compromise.\u003c\/em\u003e\u003c\/p\u003e","products":[],"url":"https:\/\/www.fullerkr.com\/collections\/carriage-bolts-din-603-marine-stainless-steel-a4.oembed","provider":"Fullerkreg Fasteners","version":"1.0","type":"link"}