{"product_id":"m10-carriage-bolts-a2-stainless-steel-din-603-cup-square-dome-head","title":"M10 Carriage Bolts A2 Stainless Steel — Cup Square Dome Head Coach Screws DIN 603","description":"\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I choose the right length for M10 carriage bolts?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A general rule is to add the thickness of all materials being joined, then add at least 1–1.5× the bolt diameter (10mm) for the nut and washer. For example, joining two 25mm (1\\\") boards typically calls for a 60mm (≈2-3\/8\\\") bolt. Always confirm the grip length before ordering.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What grade is the stainless steel used in these carriage bolts?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"These bolts are manufactured from A2 stainless steel (equivalent to 304 stainless), which offers good corrosion resistance for most outdoor and marine-adjacent environments. For highly aggressive saltwater or chemical exposure, A4 (316) grade is generally recommended instead.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can these carriage bolts be used outdoors or in wet conditions?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. A2 stainless steel provides solid resistance to rust and oxidation, making these bolts suitable for outdoor decking, fencing, pergolas, and garden structures. They are not recommended for continuous saltwater immersion — for that, A4 stainless is typically the better choice.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What thread standard do these bolts follow?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"These carriage bolts conform to DIN 603 and use the standard M10 metric coarse thread (pitch 1.5mm). They are compatible with standard M10 hex nuts, nylon lock nuts, and flat washers.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How does the cup square (carriage bolt) head prevent the bolt from spinning?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The square section of the shank, located directly beneath the dome head, is designed to bite into the wood fiber as the nut is tightened. This self-locking action holds the bolt stationary so you can apply torque from the nut side only — no need to hold the head with a second tool.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I need a washer, and should it go under the head or the nut?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"In most cases, a flat washer is placed under the nut (not under the dome head). The dome head is designed to seat directly against the workpiece surface. The washer on the nut side distributes the clamping force over a larger area, reducing the risk of the nut pulling through softer wood.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the tensile strength of A2 stainless steel carriage bolts?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A2 stainless steel fasteners typically have a tensile strength of around 500–700 MPa depending on the property class (commonly A2-50 or A2-70). For structural or load-bearing applications, confirm the required load rating with an engineer before specifying.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\n\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003eM10 Carriage Bolts in A2 Stainless Steel — Secure, Rust-Resistant Fastening for Wood and Structural Projects\u003c\/h2\u003e\n    \u003cp\u003eWhether you're building a backyard deck, assembling a pergola, hanging a gate, or tackling a timber-frame repair, loose or corroded fasteners are the last thing you want to deal with mid-project. These M10 A2 stainless steel carriage bolts are engineered for DIYers and tradespeople who need a reliable, corrosion-resistant connection that holds firm season after season — without the rust streaks left by zinc-plated alternatives.\u003c\/p\u003e\n    \u003cp\u003eEach set includes M10 cup square dome head coach screws conforming to DIN 603, manufactured from A2 (304) stainless steel. The M10 shank diameter (≈3\/8\") is paired with a square neck that self-locks into wood as you tighten. Available lengths range from 40mm (≈1-9\/16\") to 100mm (≈3-15\/16\"), sold in box quantities of 8 to 15 pieces depending on the size selected. Matching M10 hex nuts and flat washers are sold separately.\u003c\/p\u003e\n    \u003cp\u003eTypical applications include outdoor deck construction with M10 stainless carriage bolts through 2× lumber, timber pergola and arbor assembly, wooden gate hinge reinforcement, and general structural wood-to-wood fastening where a smooth, tamper-resistant dome head is required on the visible face.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-compat\"\u003e\n    \u003cspan class=\"hdiy-compat-icon\"\u003e🔩\u003c\/span\u003e\n    \u003cstrong\u003eCompatibility:\u003c\/strong\u003e Standard M10 metric coarse thread (pitch 1.5mm) — fits M10 hex nuts, nylon lock nuts, and flat washers. Conforms to \u003cstrong\u003eDIN 603\u003c\/strong\u003e. Designed primarily for through-bolting timber, plywood, and structural wood assemblies.\n  \u003c\/div\u003e\n\n  \u003ch2\u003e✅ Key Features of These M10 Stainless Steel Carriage Bolts\u003c\/h2\u003e\n  \u003cul class=\"hdiy-features\"\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e🦀\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eA2 Stainless Steel Construction\u003c\/strong\u003e — Manufactured from A2 (304) stainless steel for reliable corrosion resistance in outdoor, humid, and weather-exposed environments — a significant step up from standard zinc-plated coach screws.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e🔵\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eDIN 603 Cup Square Dome Head\u003c\/strong\u003e — The smooth, rounded dome head sits flush against the workpiece for a clean, snag-free finish on the visible face, while the square neck self-locks into wood to prevent rotation during tightening.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eMultiple Length Options\u003c\/strong\u003e — Choose from 40mm (≈1-9\/16\"), 50mm (≈2\"), 60mm (≈2-3\/8\"), 70mm (≈2-3\/4\"), 90mm (≈3-9\/16\"), or 100mm (≈3-15\/16\") to match your specific timber thickness and grip-length requirements.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eBoxed in Project-Ready Quantities\u003c\/strong\u003e — Sold in pre-counted box sets (8–15 pcs depending on length) so you can plan material quantities accurately and avoid over-ordering on smaller jobs.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eSingle-Side Installation\u003c\/strong\u003e — The self-locking square shank eliminates the need to hold the bolt head during tightening — ideal for through-bolting applications where access to both sides is limited.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e🏗️\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eVersatile Structural Use\u003c\/strong\u003e — Suited for deck framing, fence post connections, pergola beam joints, gate hardware mounting, and other outdoor wood-to-wood structural fastening where a tamper-resistant head profile is preferred.\u003c\/span\u003e\n    \u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch2\u003e📐 Technical Specifications — M10 DIN 603 Carriage Bolts\u003c\/h2\u003e\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eStandard\u003c\/th\u003e\n\u003ctd\u003eDIN 603\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eHead Type\u003c\/th\u003e\n\u003ctd\u003eCup Square (Dome \/ Mushroom) Head\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eDrive Type\u003c\/th\u003e\n\u003ctd\u003eNo drive — square neck self-locking (wrench on nut only)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eThread Diameter\u003c\/th\u003e\n\u003ctd\u003eM10 (≈3\/8\")\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eThread Pitch\u003c\/th\u003e\n\u003ctd\u003e1.5mm (metric coarse)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eAvailable Lengths\u003c\/th\u003e\n\u003ctd\u003e40mm (≈1-9\/16\"), 50mm (≈2\"), 60mm (≈2-3\/8\"), 70mm (≈2-3\/4\"), 90mm (≈3-9\/16\"), 100mm (≈3-15\/16\")\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eA2 Stainless Steel (304 equivalent)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eNatural stainless (no coating)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eTensile Strength\u003c\/th\u003e\n\u003ctd\u003eTypically 500–700 MPa (A2-50 \/ A2-70 class)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eQuantity per Box\u003c\/th\u003e\n\u003ctd\u003eSee variant options (8–15 pcs depending on length)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eCompatible Nut\u003c\/th\u003e\n\u003ctd\u003eStandard M10 hex nut, nylon lock nut (sold separately)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eRecommended Washer\u003c\/th\u003e\n\u003ctd\u003eM10 flat washer under nut (sold separately)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePrimary Application\u003c\/th\u003e\n\u003ctd\u003eTimber \/ structural wood through-bolting\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eCountry of Origin\u003c\/th\u003e\n\u003ctd\u003eContact us to confirm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n  \u003cdiv class=\"hdiy-faq\"\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow do I choose the right length for M10 carriage bolts?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eA general rule is to add the total thickness of all materials being joined, then add at least 1–1.5× the bolt diameter (10mm) to account for the nut and washer stack. For example, joining two 25mm (1\") boards typically calls for a 60mm (≈2-3\/8\") bolt. Always measure your actual grip length before selecting a size. If you're between sizes, go longer — you can always add a washer to take up slack.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat grade is the stainless steel, and how does it compare to zinc-plated bolts?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eThese bolts are made from A2 stainless steel (equivalent to 304 stainless). Compared to standard zinc-plated or hot-dip galvanized carriage bolts, A2 stainless offers superior long-term corrosion resistance without the white rust or coating degradation common with zinc finishes — particularly in humid, coastal, or outdoor environments. For highly aggressive saltwater or chemical exposure, A4 (316) stainless is generally the better choice.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan these carriage bolts be used outdoors or in wet conditions?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eYes. A2 stainless steel provides solid resistance to rust and oxidation, making these bolts well-suited for outdoor decking, fencing, pergolas, garden structures, and similar applications. They are not recommended for continuous saltwater immersion or highly corrosive chemical environments — for those conditions, A4 (316) stainless is typically the better specification.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat thread standard do these bolts follow, and what nuts are compatible?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eThese carriage bolts conform to DIN 603 and use the standard M10 metric coarse thread (pitch 1.5mm). They are compatible with any standard M10 hex nut, nylon insert lock nut (Nyloc), or flange nut. A flat M10 washer under the nut is recommended to distribute clamping load and protect the wood surface.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow does the cup square head prevent the bolt from spinning?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eThe square section of the shank, located directly beneath the dome head, is designed to bite into the wood fiber as the nut is tightened. This self-locking action holds the bolt stationary so you can apply torque from the nut side only — no need to hold the head with a second tool. This makes them especially practical when the bolt head is recessed or on the underside of a structure.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eDo I need a washer, and should it go under the head or the nut?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eIn most cases, a flat washer is placed under the nut (not under the dome head). The dome head is designed to seat directly against the workpiece surface. The washer on the nut side distributes the clamping force over a larger area, reducing the risk of the nut pulling through softer wood. For hardwoods or steel-to-wood connections, a washer may not be strictly necessary but is still good practice.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is the load-bearing or tensile strength of these bolts?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eA2 stainless steel fasteners typically carry a tensile strength of around 500–700 MPa, depending on the property class (A2-50 or A2-70). For structural or load-bearing applications — such as deck ledger connections or load-path timber joints — always confirm the required load rating with a licensed engineer and consult local building codes before specifying fastener size and quantity.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-cta\"\u003e\n    🛒 Select your \u003cstrong\u003elength and quantity\u003c\/strong\u003e above, then add to cart — ships from our US warehouse.\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"HomeDIYer","offers":[{"title":"M10 \u0026 10mm \/ 40mm \/ 15PCS\u0026BOX","offer_id":52308590625042,"sku":"KAYFST029-13","price":13.15,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 50mm \/ 10PCS\u0026BOX","offer_id":52308590657810,"sku":"KAYFST029-14","price":11.52,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 60mm \/ 10PCS\u0026BOX","offer_id":52308590690578,"sku":"KAYFST029-15","price":12.17,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 70mm \/ 10PCS\u0026BOX","offer_id":52308590723346,"sku":"KAYFST029-16","price":13.26,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 90mm \/ 10PCS\u0026BOX","offer_id":52308590756114,"sku":"KAYFST029-17","price":15.44,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 100mm \/ 8PCS\u0026BOX","offer_id":52308590788882,"sku":"KAYFST029-18","price":14.44,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/1_5_a8d5755f-b186-4fdc-9638-ca6eb1c74279.jpg?v=1780501869","url":"https:\/\/homediyer.com\/products\/m10-carriage-bolts-a2-stainless-steel-din-603-cup-square-dome-head","provider":"HomeDIYer","version":"1.0","type":"link"}