{"product_id":"m10-carriage-bolts-a2-70-stainless-steel-coach-screws","title":"M10 Carriage Bolts A2-70 Stainless Steel | Round Head Square Neck Coach Screws","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 bolt length for my project?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Generally, the bolt length should equal the total thickness of the materials being joined plus enough thread engagement for the nut — typically an additional 1–2× the bolt diameter. For example, joining two 20mm boards with M10 bolts would typically call for a 50mm (≈2\\u201d) bolt. Always measure your stack-up before ordering.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does A2-70 mean and how strong are these bolts?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A2 refers to the austenitic stainless steel grade (equivalent to 304 stainless), and 70 indicates a minimum tensile strength of 700 MPa. This makes them suitable for structural and load-bearing connections in most residential and light commercial applications.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Are these carriage bolts suitable for outdoor or marine use?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A2 stainless steel offers excellent corrosion resistance and is generally suitable for outdoor, coastal, and humid environments. For highly aggressive marine or chemical environments, A4 (316) stainless is typically recommended instead.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What thread standard do these bolts use?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"These are M10 metric coarse thread bolts, conforming to ISO 8677 \/ DIN 603 standards. They are compatible with standard M10 hex nuts and washers. They are not compatible with UNC\/UNF inch-thread fasteners.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the purpose of the square neck under the round head?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The square neck is designed to embed into wood or soft materials as the nut is tightened, preventing the bolt from spinning. This allows one-person installation — no need to hold the bolt head with a wrench.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Which pack size should I choose?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Pack sizes of 8, 10, or 15 pieces are available depending on the bolt length. For small repairs or prototyping, a smaller pack is cost-effective. For larger structural builds such as decking or fencing, ordering a larger quantity per length reduces per-unit cost and shipping trips.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I need a washer with these carriage bolts?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A flat washer under the nut is generally recommended to distribute the clamping load and protect the surface of the material. The domed round head on the bolt side typically does not require a washer, as it already provides a broad bearing surface.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\n\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003c!-- ① OVERVIEW --\u003e\n  \u003ch2\u003eM10 Stainless Steel Carriage Bolts — Secure, Rust-Resistant Fastening for Wood and Structural Assemblies\u003c\/h2\u003e\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003cp\u003eWhether you're building a backyard deck, assembling a pergola, or reinforcing a fence post, stripped or rusted bolts can turn a weekend project into a costly headache. These M10 carriage bolts are made from A2-70 stainless steel — a grade chosen by contractors and serious DIYers who need reliable, long-lasting fasteners that won't let them down after the first rainy season.\u003c\/p\u003e\n    \u003cp\u003eEach pack contains M10 round head square neck coach screws in your chosen bolt length and quantity. The thread diameter is M10 (10mm), with bolt lengths available from 40mm (≈1-9\/16\") to 100mm (≈3-15\/16\"). Packs are available in 8, 10, or 15 pieces depending on the length selected, making it easy to order exactly what your job requires.\u003c\/p\u003e\n    \u003cp\u003eTypical applications include timber deck construction, wooden gate and fence assembly, playground equipment fastening, and structural wood-to-wood connections in sheds and outbuildings — anywhere you need a tamper-resistant, smooth-headed bolt that locks itself against rotation during tightening.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- ② COMPATIBILITY BAR --\u003e\n  \u003cdiv class=\"hdiy-compat\"\u003e\n    \u003cspan class=\"hdiy-compat-icon\"\u003e🔩\u003c\/span\u003e\n    \u003cstrong\u003eCompatibility:\u003c\/strong\u003e M10 metric coarse thread (ISO 8677 \/ DIN 603). Fits standard M10 hex nuts and flat washers. \u003cstrong\u003eNot compatible\u003c\/strong\u003e with UNC\/UNF inch-thread fasteners. Confirm your nut thread standard before ordering.\n  \u003c\/div\u003e\n\n  \u003c!-- ③ KEY FEATURES --\u003e\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\u003cspan\u003e\u003cstrong\u003eA2-70 Stainless Steel Construction\u003c\/strong\u003e — Manufactured to ISO 3506 A2-70, delivering a minimum tensile strength of 700 MPa with inherent corrosion resistance for outdoor wood fastening applications.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔘\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eRound Dome Head Profile\u003c\/strong\u003e — The low-profile domed head sits flush and smooth on the surface, eliminating sharp edges and providing a clean finish on visible faces of decking, furniture, and gates.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⬛\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eAnti-Rotation Square Neck\u003c\/strong\u003e — The square shank under the head bites into timber as the nut is driven, locking the bolt in place without needing a second tool — ideal for single-person installation in tight spaces.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eMultiple Length Options\u003c\/strong\u003e — Available in 40mm, 50mm, 60mm, 70mm, 90mm, and 100mm to cover a wide range of timber thicknesses, from single-board connections to multi-layer structural assemblies.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eJob-Matched Pack Quantities\u003c\/strong\u003e — Choose 8, 10, or 15 pieces per box based on your project scale, reducing waste and letting you order the right amount for deck boards, fence rails, or framing connections.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🌧️\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eOutdoor and Coastal Durability\u003c\/strong\u003e — A2 stainless resists rust and staining in rain-exposed, humid, and coastal environments, making these coach screws a dependable choice for exterior structural wood connections.\u003c\/span\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003c!-- ④ TECHNICAL SPECIFICATIONS --\u003e\n  \u003ch2\u003e📐 Technical Specifications — M10 Round Head Square Neck Carriage Bolts\u003c\/h2\u003e\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eProduct Type\u003c\/th\u003e\n\u003ctd\u003eCarriage Bolt (Coach Screw \/ Round Head Square Neck Bolt)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eStandard\u003c\/th\u003e\n\u003ctd\u003eISO 8677 \/ DIN 603\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMaterial Grade\u003c\/th\u003e\n\u003ctd\u003eA2-70 Stainless Steel (ISO 3506, equiv. 304 SS)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eThread Diameter\u003c\/th\u003e\n\u003ctd\u003eM10 (10mm \/ ≈3\/8\")\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eThread Type\u003c\/th\u003e\n\u003ctd\u003eMetric Coarse (ISO standard pitch)\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\u003eHead Style\u003c\/th\u003e\n\u003ctd\u003eRound Dome Head\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eNeck Style\u003c\/th\u003e\n\u003ctd\u003eSquare Neck (anti-rotation)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eTensile Strength\u003c\/th\u003e\n\u003ctd\u003e700 MPa minimum (A2-70 rating)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eMill \/ Natural Stainless (no coating)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePack Quantities\u003c\/th\u003e\n\u003ctd\u003e8 PCS, 10 PCS, or 15 PCS (varies by length — see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eCompatible Nut\u003c\/th\u003e\n\u003ctd\u003eStandard M10 Hex 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\u003eDrive Method\u003c\/th\u003e\n\u003ctd\u003eNo drive required on bolt head — tighten nut with 17mm wrench or socket\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eCountry of Origin\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-note\"\u003e\n    \u003cspan class=\"hdiy-note-icon\"\u003e⚠️\u003c\/span\u003e\n    \u003cstrong\u003eSpec Note:\u003c\/strong\u003e Thread pitch and exact head\/neck dimensions follow DIN 603 standards. If your application requires confirmed dimensional tolerances, contact us to confirm before ordering.\n  \u003c\/div\u003e\n\n  \u003c!-- ⑤ FAQ --\u003e\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 bolt length for my project?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eGenerally, the bolt length should equal the total thickness of the materials being joined plus enough thread engagement for the nut — typically an additional 1–2× the bolt diameter. For M10 bolts, that means adding roughly 10–20mm beyond your material stack. For example, joining two 20mm boards would typically call for a 50mm (≈2\") bolt. Always measure your full stack-up — including any washers — before selecting a length.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat does A2-70 mean and how strong are these bolts?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eA2 refers to the austenitic stainless steel alloy group (equivalent to 304 stainless steel), and 70 indicates a minimum tensile strength of 700 MPa per ISO 3506. This makes them suitable for structural and load-bearing wood connections in most residential and light commercial applications, including decking, fencing, and timber framing.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eAre these carriage bolts suitable for outdoor or marine use?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eA2 stainless steel offers excellent corrosion resistance and is generally suitable for outdoor, coastal, and humid environments — including rain-exposed decks, garden structures, and fence assemblies. For highly aggressive marine or chemical environments where saltwater immersion is frequent, A4 (316) stainless is typically recommended instead.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat thread standard do these bolts use — are they compatible with standard nuts?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eThese are M10 metric coarse thread bolts conforming to ISO 8677 \/ DIN 603. They are compatible with standard M10 metric hex nuts and flat washers. They are \u003cstrong\u003enot\u003c\/strong\u003e compatible with UNC or UNF inch-thread fasteners. If you are unsure of your existing hardware's thread standard, check the nut markings or measure the thread pitch before ordering.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is the purpose of the square neck under the round head?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eThe square neck is designed to embed into wood or soft materials as the nut is tightened, preventing the bolt from spinning in place. This allows single-person installation — you can drive the nut from one side without needing to hold the bolt head with a second wrench. It is particularly useful when the bolt head is recessed or in a hard-to-reach location.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhich pack size should I choose — 8, 10, or 15 pieces?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003ePack size varies by bolt length. Shorter bolts (40mm) are available in 15-piece packs, mid-range lengths (50mm–70mm) in 10-piece packs, and longer bolts (100mm) in 8-piece packs. For small repairs or prototyping, a single pack is typically sufficient. For larger builds such as full deck sections or fence runs, consider ordering multiple packs to reduce per-unit cost and avoid mid-project shortages.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eDo I need a washer with these carriage bolts?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eA flat washer under the nut is generally recommended to distribute the clamping load across a wider surface area and protect the timber from the nut bearing directly into the grain. The domed round head on the bolt side typically does not require a washer, as it already provides a broad, smooth bearing surface. Washers are sold separately.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n  \u003c\/div\u003e\n\n  \u003c!-- ⑥ CTA BAR --\u003e\n  \u003cdiv class=\"hdiy-cta\"\u003e\n    🛒 Select your \u003cstrong\u003ethread diameter, bolt length, and pack 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":52308509851922,"sku":"KAYFST029-13","price":13.15,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 50mm \/ 10PCS\u0026BOX","offer_id":52308509884690,"sku":"KAYFST029-14","price":11.52,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 60mm \/ 10PCS\u0026BOX","offer_id":52308509917458,"sku":"KAYFST029-15","price":12.17,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 70mm \/ 10PCS\u0026BOX","offer_id":52308509950226,"sku":"KAYFST029-16","price":13.26,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 90mm \/ 10PCS\u0026BOX","offer_id":52308509982994,"sku":"KAYFST029-17","price":15.44,"currency_code":"USD","in_stock":true},{"title":"M10 \u0026 10mm \/ 100mm \/ 8PCS\u0026BOX","offer_id":52308510015762,"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_be7ba794-bbc4-4a97-b34e-b18d51e142dd.jpg?v=1780502216","url":"https:\/\/homediyer.com\/products\/m10-carriage-bolts-a2-70-stainless-steel-coach-screws","provider":"HomeDIYer","version":"1.0","type":"link"}