{"product_id":"simpson-strong-tie-strong-drive-sdhr-combo-head-screw-0-315-in-x-4-in-blue-zinc-100-pack-sdhr31400","title":"Simpson Strong-Tie Strong-Drive SDHR COMBO-HEAD Screw, 0.315-in. x 4-in., Blue Zinc, 100-Pack (SDHR31400)","description":"\u003csection data-aplus\u003e\n\u003cdetails id=\"product-features\" class=\"acc\" open\u003e\n  \u003csummary\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"features\"\u003e\n      \u003cdiv class=\"card\"\u003e\n        \u003cdiv class=\"card-inside\"\u003e\n          \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/material.svg\" alt=\"material\" class=\"aplusicon\"\u003e\n        \u003c\/div\u003e\n        \u003cdiv\u003e\u003cstrong\u003eBuilt for Steel-to-Wood\u003c\/strong\u003e\u003c\/div\u003e\n        \u003cdiv class=\"feature-card\"\u003eThis Simpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head Screw is made for steel side plate to wood connections in mass timber and cross-laminated timber work. That means a fastener matched to the job instead of forcing a general-purpose structural screw into a connection it was not built for.\u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"card\"\u003e\n        \u003cdiv class=\"card-inside\"\u003e\n          \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/tool-free-change.svg\" alt=\"tool-free-change\" class=\"aplusicon\"\u003e\n        \u003c\/div\u003e\n        \u003cdiv\u003e\u003cstrong\u003eDual Drive Options\u003c\/strong\u003e\u003c\/div\u003e\n        \u003cdiv class=\"feature-card\"\u003eThe combo head can be driven with either a hex head or a T40 six-lobe driver bit. That gives installers more flexibility on site when tool setup, access, or preferred drive style changes from one connection to the next.\u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"card\"\u003e\n        \u003cdiv class=\"card-inside\"\u003e\n          \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/drill-bits.svg\" alt=\"drill-bits\" class=\"aplusicon\"\u003e\n        \u003c\/div\u003e\n        \u003cdiv\u003e\u003cstrong\u003eFast Starts, Less Prep\u003c\/strong\u003e\u003c\/div\u003e\n        \u003cdiv class=\"feature-card\"\u003eA Type-17 point helps the screw start quickly, lowers installation torque, and eliminates predrilling in most applications. The partially threaded shank and knurl are there to pull members together while maintaining strong withdrawal performance.\u003c\/div\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-overview\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003eOverview\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\" data-product-summary\u003e\n    \u003cp\u003eThe \u003cstrong\u003eSimpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head Screw\u003c\/strong\u003e is a partially threaded structural screw for steel-to-wood connections in engineered wood, cross-laminated timber, and mass timber assemblies. This is a \u003cstrong\u003estructural screw designed for steel side plate to wood fastening in interior mass timber construction\u003c\/strong\u003e. Model Number: \u003cstrong\u003eSDHR31400\u003c\/strong\u003e. In this size, you are getting a 4 inch blue-zinc coated fastener with a 0.315 inch shank diameter, 0.669 inch head diameter, Type-17 point, and packaging quantity of 100.\u003c\/p\u003e\n    \u003cp\u003eWhat matters on the job is how this screw installs and how the connection behaves once it is in. The SDHR31400 uses a heavy-duty partially threaded shaft with knurl so it can pull structural members together instead of just spinning in place and hoping the joint closes up. That matters in steel-to-wood connections where fit-up, clamping action, and pull-out resistance are not small details. They are the whole point.\u003c\/p\u003e\n    \u003cp\u003eThe Type-17 point is there for a reason. It helps the screw start fast, reduces installation torque, and removes the need for predrilling in most applications. In real terms, that means less setup time and less fight driving into engineered wood on repetitive installs. When you are setting a run of fasteners into CLT or other mass timber members, easier starts and lower drive resistance add up quickly.\u003c\/p\u003e\n    \u003cp\u003eThe combo-head design gives you two practical drive choices: T40 six-lobe or hex-head. That is more than a convenience feature. On some connections, a bit-driven setup gives better engagement and control. On others, using a hex socket may be the better move depending on your access and tool setup. Simpson also calls out a deep T40 recess for a secure drive, which is exactly what you want in a structural fastener this size.\u003c\/p\u003e\n    \u003cp\u003eFor interior applications, the blue-zinc coating matches the intended service environment. This is not pitched as an exterior corrosion solution. It is an interior-grade fastener for dry-service conditions where the focus is structural performance in engineered wood connections. Used where it is meant to be used, that coating and design package make sense.\u003c\/p\u003e\n    \u003cp\u003eThe SDHR31400 is specifically tied to steel side plate applications and engineered wood construction, not generic deck work or everyday framing. Simpson lists it for steel-to-wood connections and describes the line as designed for metal-to-wood connections in mass timber construction and cross-laminated timber assemblies. If you are working on CLT panels, glulam, or other engineered wood members with steel hardware, this screw is in its lane.\u003c\/p\u003e\n    \u003cp\u003eDimensionally, this model sits in the SDHR31 group with a 4 inch overall length and 2 1\/8 inch thread length. That makes it the shorter of the SDHR31 options shown in the product table, which can be useful where connection design, member thickness, or required penetration call for the 4 inch version rather than the 6 1\/4 inch model. The larger 0.315 inch shank diameter and 0.669 inch head diameter also separate it from the smaller SDHR27 versions.\u003c\/p\u003e\n    \u003cp\u003eWho should buy it? This screw makes sense for builders, timber crews, installers, and engineers sourcing approved structural fasteners for interior steel-to-wood connections in mass timber work. If you need a screw built around engineered wood, steel side plates, strong pull-together action, and flexible drive options, the Simpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head Screw is a purpose-built answer, not a workaround.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-benefits\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003eMade for Mass Timber Connections\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"row\"\u003e\n      \u003cdiv class=\"img\"\u003e\n        \u003cimg src=\"https:\/\/cdn.anglera.com\/assets\/74d6ed76-fe0d-4d23-a9db-1f8749ca9ef2\/10497948352806_48c5e01d69e5.jpg\" alt=\"Simpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head Screw installed through a red steel side plate into cross-laminated timber in a mass timber connection\" class=\"tnblock-img\"\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"copy\"\u003e\n        \u003cp\u003eThis screw is built around the kind of steel-to-wood connection you see in CLT and other engineered wood assemblies. It is not trying to be everything. It is trying to do this job right.\u003c\/p\u003e\n        \u003cul\u003e\n          \u003cli\u003eDesigned for use with steel side plates\u003c\/li\u003e\n          \u003cli\u003eListed for steel-to-wood connections in engineered wood applications\u003c\/li\u003e\n        \u003c\/ul\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-benefits-2\" class=\"acc flip\"\u003e\n  \u003csummary\u003e\u003ch2\u003eSecure Drive When Torque Goes Up\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"row\"\u003e\n      \u003cdiv class=\"img\"\u003e\n        \u003cimg src=\"https:\/\/cdn.anglera.com\/assets\/74d6ed76-fe0d-4d23-a9db-1f8749ca9ef2\/10497948352806_ef2f544ab643.jpg\" alt=\"Close-up of the Simpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head Screw head showing the deep T40 six-lobe recess and hex head for structural fastening\" class=\"tnblock-img\"\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"copy\"\u003e\n        \u003cp\u003eThe head design is one of the big reasons this fastener stands out. You get a deep T40 six-lobe recess for positive engagement, plus a hex-head option when that setup makes more sense for your tools or access.\u003c\/p\u003e\n        \u003cul\u003e\n          \u003cli\u003eDrive type: T40 six-lobe or hex-head\u003c\/li\u003e\n          \u003cli\u003eCombination head gives installers more flexibility on site\u003c\/li\u003e\n        \u003c\/ul\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-benefits-3\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003eStarts Fast and Pulls Tight\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"row\"\u003e\n      \u003cdiv class=\"img\"\u003e\n        \u003cimg src=\"https:\/\/cdn.anglera.com\/assets\/74d6ed76-fe0d-4d23-a9db-1f8749ca9ef2\/10497948352806_9c0eea0f3dbc.jpg\" alt=\"Simpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head structural screw on a white background showing partially threaded shank, knurl, and Type-17 point\" class=\"tnblock-img\"\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"copy\"\u003e\n        \u003cp\u003eThe business end matters here. The partially threaded shaft, knurl, and Type-17 point work together to help the screw start cleaner, drive with less effort, and draw members together.\u003c\/p\u003e\n        \u003cul\u003e\n          \u003cli\u003eType-17 point reduces installation torque and avoids predrilling in most applications\u003c\/li\u003e\n          \u003cli\u003ePartially threaded shank with knurl is designed to improve pull-together action and pull-out resistance\u003c\/li\u003e\n        \u003c\/ul\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-whats-included\" class=\"acc\" open\u003e\n  \u003csummary\u003e\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"tnincluded-wrapper\"\u003e\n      \u003cul\u003e\n        \u003cli\u003e(100) Simpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head Screws\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-key-specifications\" class=\"acc\" open\u003e\n  \u003csummary\u003e\u003ch2\u003eKey Specifications\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003ctable class=\"aplusspecs\"\u003e\n      \u003ctr\u003e\n        \u003cth\u003eLength\u003c\/th\u003e\n        \u003ctd\u003e4 in.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003eShank Diameter\u003c\/th\u003e\n        \u003ctd\u003e0.315 in.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003eHead Diameter\u003c\/th\u003e\n        \u003ctd\u003e0.669 in.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003eThread Length\u003c\/th\u003e\n        \u003ctd\u003e2 1\/8 in.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003eDrive Type\u003c\/th\u003e\n        \u003ctd\u003eT40 6-Lobe or Hex-Head\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003eHead Type\u003c\/th\u003e\n        \u003ctd\u003eCombination\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003ePoint Type\u003c\/th\u003e\n        \u003ctd\u003eType-17 Point\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003eCoating \/ Material\u003c\/th\u003e\n        \u003ctd\u003eBlue-Zinc Coated\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003cth\u003ePackaging Quantity\u003c\/th\u003e\n        \u003ctd\u003e100\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-compatibility\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003eCompatibility\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"compat-list\"\u003e\n      \u003cdiv class=\"compat-row\"\u003e\n        \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/chuck-type.svg\" alt=\"chuck-type\" class=\"icon-sm\"\u003e\n        \u003cdiv\u003e\n          \u003cstrong\u003eDriver Interface\u003c\/strong\u003e\n          \u003cdiv class=\"compat-detail\"\u003eAccepts either a T40 six-lobe driver or a hex-head driving setup.\u003c\/div\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"compat-row\"\u003e\n        \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/drill-bits.svg\" alt=\"drill-bits\" class=\"icon-sm\"\u003e\n        \u003cdiv\u003e\n          \u003cstrong\u003eReplacement Bit\u003c\/strong\u003e\n          \u003cdiv class=\"compat-detail\"\u003eReplacement six-lobe bit reference: BIT40T-134-R2.\u003c\/div\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"compat-row\"\u003e\n        \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/material.svg\" alt=\"material\" class=\"icon-sm\"\u003e\n        \u003cdiv\u003e\n          \u003cstrong\u003eConnection Type\u003c\/strong\u003e\n          \u003cdiv class=\"compat-detail\"\u003eDesigned for steel side plate to wood connections in engineered wood and mass timber assemblies.\u003c\/div\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-applications-uses\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003eBuilt For\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"tags\"\u003e\n      \u003cspan class=\"tag\"\u003eMass Timber Construction\u003c\/span\u003e\n      \u003cspan class=\"tag\"\u003eCross-Laminated Timber\u003c\/span\u003e\n      \u003cspan class=\"tag\"\u003eEngineered Wood\u003c\/span\u003e\n      \u003cspan class=\"tag\"\u003eSteel-to-Wood Connections\u003c\/span\u003e\n      \u003cspan class=\"tag\"\u003eStructural Fastening\u003c\/span\u003e\n      \u003cspan class=\"tag\"\u003eConstruction\u003c\/span\u003e\n      \u003cspan class=\"tag\"\u003eGeneral Contracting\u003c\/span\u003e\n      \u003cspan class=\"tag\"\u003eInterior Applications\u003c\/span\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-pro-tips\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003ePro Tip\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"tip-row\"\u003e\n      \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/specs.svg\" alt=\"specs\" class=\"icon-lg\"\u003e\n      \u003cp class=\"tip-text\"\u003eIf your crew switches between drive setups, keep both a T40 bit and the right hex socket on hand. The combo head gives you that flexibility, and using the drive style that best matches access around the steel plate can make installation smoother and reduce cam-out.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-tool-nut-take\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003eTool Nut's Take\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cdiv class=\"eyebrow\"\u003eTool Nut's Take\u003c\/div\u003e\n    \u003ch3\u003eSimpson Strong-Tie SDHR31400 Strong-Drive SDHR Combo-Head Screw for serious timber connections\u003c\/h3\u003e\n    \u003cp\u003eThis is the kind of fastener you buy when the connection actually matters and you want a screw designed around steel-to-wood structural work, not a general screw trying to play up a class.\u003c\/p\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWho it's for:\u003c\/strong\u003e Builders, timber installers, and spec-driven buyers working in CLT, glulam, and other engineered wood connections with steel side plates.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWhy it stands out:\u003c\/strong\u003e The combo head is smart, the Type-17 point speeds installation, and the partially threaded shank is built to pull members together instead of just occupying a hole.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWorth knowing:\u003c\/strong\u003e This is an interior-grade blue-zinc coated fastener, so keep the application aligned with the service environment it was designed for.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails id=\"product-faqs\" class=\"acc\"\u003e\n  \u003csummary\u003e\u003ch2\u003eCommon Questions\u003c\/h2\u003e\u003c\/summary\u003e\n  \u003cdiv class=\"acc-body\"\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWhat is this screw designed for?\u003c\/strong\u003e It is designed for steel-to-wood connections in engineered wood, mass timber construction, and cross-laminated timber assemblies.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eCan it be driven with more than one tool setup?\u003c\/strong\u003e Yes. The SDHR31400 can be driven with either a T40 six-lobe driver bit or a hex-head driving setup.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eDoes it usually require predrilling?\u003c\/strong\u003e Simpson states that the Type-17 point ensures fast starts, reduces installation torque, and eliminates the need for predrilling in most applications.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eIs this a fully threaded screw?\u003c\/strong\u003e No. It is a partially threaded structural fastener.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/section\u003e","brand":"Simpson Strong-Tie","offers":[{"title":"Default Title","offer_id":52999305756966,"sku":"SDHR31400","price":199.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0933\/1582\/5958\/files\/SDHR31400_00707392012078_Feature_Closeup_Photo_01_b2b86393-fff9-49f7-81dd-b8df5adef3b9.jpg?v=1779135458","url":"https:\/\/www.toolnut.com\/products\/simpson-strong-tie-strong-drive-sdhr-combo-head-screw-0-315-in-x-4-in-blue-zinc-100-pack-sdhr31400","provider":"Tool Nut","version":"1.0","type":"link"}