{"product_id":"imscrews-5-16-18-x-3-carriage-bolts-304-stainless-steel-18-8-full-thread-structural-fasteners-for-4x4-posts-decks-timber-construction-20-pcs","title":"IMSCREWS 5\/16-18 x 3 Carriage Bolts, 304 Stainless Steel (18-8), Full Thread Structural Fasteners for 4x4 Posts, Decks \u0026 Timber Construction, 20 PCS","description":"\u003cp\u003e\u003cstrong\u003eIMSCREWS 5\/16\"-18 x 3\" Heavy-Duty 304 Stainless Steel Carriage Bolts (20 PCS)\u003c\/strong\u003e\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003eSubstantial Strength for 4x4 Posts and Timber Construction\u003c\/strong\u003e\u003cbr\u003eThe IMSCREWS 5\/16\" x 3\" carriage bolt is engineered for structural projects requiring significant shear resistance and a professional, tamper-resistant finish. With a robust 5\/16-inch diameter and a precise 3-inch length, these bolts are the \u003cstrong\u003eideal\u003c\/strong\u003e choice for securing deck railings to 4x4 posts or connecting dual-layered 2x4 lumber (actual 3\" thickness). The full thread design ensures maximum versatility, providing a \u003cstrong\u003esnug\u003c\/strong\u003e and permanent connection across various material combinations. Built for durability, they offer the stability required for outdoor structures, pergolas, and heavy-duty timber framing.\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003eHigh Durability and Safety-Focused Design\u003c\/strong\u003e\u003cbr\u003eForged from premium 18-8 (304) stainless steel, these fasteners are highly resistant to rust and corrosion in coastal or humid environments. The smooth round head offers a \u003cstrong\u003eclean\u003c\/strong\u003e, low-profile appearance that reduces snagging hazards, making them a safe choice for children's playground equipment, residential benches, and exposed deck stairs. The integrated square neck prevents the bolt from spinning during installation, allowing for easy, one-sided fastening with a single wrench from the nut side.\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003eSpecifications:\u003c\/strong\u003e\u003cbr\u003e- Thread Size: 5\/16\"-18 Coarse (UNC); Length: 3\" (Measured from Under Head)\u003cbr\u003e- Material: 304 (18-8) Stainless Steel; Full Thread\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003ePro-Tips:\u003c\/strong\u003e\u003cbr\u003e1. Use a 5\/16\" drill bit to ensure a \u003cstrong\u003esnug\u003c\/strong\u003e, structural fit for the square neck.\u003cbr\u003e2. Pair with stainless steel flat washers and hex nuts on the nut side to distribute structural load and protect wood fibers.\u003c\/p\u003e\u003ch3\u003eKey Features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eIndustrial 3 Penetration: Expertly designed for through-bolting thick timbers, such as joining two 2x4s (3 total) or securing heavy-duty brackets to structural 4x4 posts.\u003c\/li\u003e\n\u003cli\u003eReinforced 5\/16 Strength: The 5\/16 shank offers a significant boost in load-bearing and shear resistance over standard 1\/4 bolts, ensuring safety in structural applications.\u003c\/li\u003e\n\u003cli\u003eMarine-Grade 304 Stainless: Forged from 18-8 (304) stainless steel, providing superior rust protection in coastal environments, humid gardens, and with treated lumber.\u003c\/li\u003e\n\u003cli\u003eTamper-Resistant Safety Head: The smooth round head offers a clean finish without sharp edges¡ªideal for public benches, playgrounds, and child-safe backyard structures.\u003c\/li\u003e\n\u003cli\u003eSelf-Locking Square Neck: The precision square shoulder bites firmly into wood fibers, locking the bolt so you can easily tighten the nut with one wrench from the opposite side.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eASIN:\u003c\/strong\u003e B0F2F8G9Q9\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInternal SKU:\u003c\/strong\u003e IMS0809\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 5\/16\"-18 x 3\"\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Stainless Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Stainless Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHead Style:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 20\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"IMSCREWS","offers":[{"title":"Default Title","offer_id":57034019373222,"sku":"B0F2F8G9Q9","price":16.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0271\/2784\/0903\/files\/51ZaVl7AlSL_4c884351-631c-4bd6-88e4-c82c3d17c373.jpg?v=1787034827","url":"https:\/\/www.imscrews.com\/products\/imscrews-5-16-18-x-3-carriage-bolts-304-stainless-steel-18-8-full-thread-structural-fasteners-for-4x4-posts-decks-timber-construction-20-pcs","provider":"IMSCREWS","version":"1.0","type":"link"}