Simpson Strong-Drive SDCF TIMBER-CF Screw - 0.315 in. x 4-3/4 in. T40, E-Coat by Simpson Strong-Tie is a heavy-duty structural screw engineered for cross-laminated timber (CLT), mass timber construction, and demanding general interior wood fastening applications. The black e-coat electrocoating finish delivers a clean, construction-durable nonmetallic surface treatment that enhances aesthetics while providing corrosion resistance for interior dry-service environments. With a SawTooth point for fast starts, a fully threaded shank for maximum withdrawal resistance, and a flat head with underhead nibs for flush countersinking, this timber screw is built for performance in heavy timber, glulam, engineered wood, and multi-ply fastening applications alike.

Key Features

• Flat head with underhead nibs - enables clean countersinking so the screw seats flush with the wood surface, eliminating surface tear-out and producing a professional finish in exposed timber applications
• Fully threaded heavy-duty shank - the complete thread engagement along the 4 1/4 in. thread length provides superb withdrawal resistance, keeping connections tight under load in mass timber and engineered wood assemblies
• SawTooth point - starts fast and drives easily, reducing installation torque and eliminating the need for predrilling in most applications, saving time on the job site
• Black e-coat electrocoating finish - provides a construction-durable nonmetallic coating for corrosion resistance in interior dry-service applications, while also contributing to a visually clean result in finished timber work
• Deep T40 6-lobe drive recess - the deep engagement of the 6-lobe recess delivers a secure, high-torque drive with reduced cam-out, making installation more reliable and less fatiguing
• Compliant with CSA O86:24 hydrogen embrittlement requirements - the optimized hardness profile helps mitigate the risk of brittle fracture, supporting long-term structural reliability
• 0.315 in. overall diameter, 0.230 in. shank diameter - sized for structural performance in timber framing, beam reinforcement, and connector fastening without overloading the surrounding wood fiber

Why This Product

• Designed specifically for cross-laminated timber and mass timber construction - the SawTooth point, fully threaded shank, and flat head with nibs work together to deliver fast installation with strong, flush results in CLT panels, glulam beams, and engineered wood assemblies without predrilling in most cases
• The black e-coat electrocoating satisfies both functional and aesthetic demands - it provides corrosion resistance for interior dry-service conditions while delivering the clean, dark appearance that is increasingly preferred in exposed heavy timber and architectural mass timber projects
• CSA O86:24 compliance for hydrogen embrittlement - the optimized hardness profile addresses a critical structural concern in high-strength screws, making this fastener a dependable choice for structural timber applications where long-term performance matters
• Versatile across a wide range of interior wood construction tasks - from fastening wall-to-wall and stud-to-plate connections to securing Simpson Strong-Tie connectors, surface splines, butt joists, and floor-to-floor assemblies, this screw covers a broad scope of structural and framing work

Specifications

• Brand: Simpson Strong-Tie
• Product Name: Strong-Drive SDCF TIMBER-CF Screw
• Length: 4 3/4 in.
• Shank Diameter: 0.230 in.
• Head Diameter: 0.590 in.
• Thread Length: 4 1/4 in.
• Head Type: Flat Head with Nibs
• Drive Type: T40 6-Lobe
• Point Type: SawTooth Point
• Coating: E-coat Electrocoating
• Finish: E-coat Electrocoating
• Color: Black