Simpson Strong-Drive SDCFC TIMBER-CFC Screw - 0.315 in. x 4-3/4 in. T40, E-Coat by Simpson Strong-Tie is a heavy-duty structural wood screw engineered for demanding timber framing, mass timber, and engineered wood applications. The redesigned SDCFC screw delivers a fully threaded shank for superior withdrawal resistance, a compact cylinder head that sits flush or countersinks cleanly, and a SawTooth point that starts fast and drives easily - eliminating the need for predrilling in most applications. The black e-coat electrocoating finish combines construction-durable corrosion resistance with a refined aesthetic, making this screw a reliable choice wherever large wood members need to be fastened with confidence.

Key Features

• Compact cylinder head - helps the screw countersink for a clean, flush finish whether left exposed or driven below the surface, keeping the finished appearance professional
• Heavy-duty, fully-threaded shank (0.230 in. shank diameter) - provides superb withdrawal resistance across the full shank length, giving structural connections the holding power needed in large timber and engineered wood assemblies
• SawTooth point - enables fast starts and easy driving while reducing installation torque, so the screw seats quickly without splitting heavy members or requiring predrilled pilot holes in most applications
• Black e-coat electrocoating finish - delivers a construction-durable nonmetallic coating for corrosion resistance in interior dry-service applications, while the dark color blends in wherever the screw head remains visible
• Deep T40 6-lobe recess - creates a secure, high-torque connection between bit and screw head, reducing cam-out during installation for smoother, more controlled driving
• Compliant with CSA O86:24 hydrogen embrittlement requirements - the optimized hardness profile and e-coat finish together help mitigate brittle fracture risk, supporting long-term structural reliability
• 4-3/4 in. overall length with 4-1/4 in. thread length - maximizes thread engagement deep into the receiving member for strong, lasting connections in beam reinforcement, glulam, and cross-laminated timber (CLT)

Why This Product

• Engineered specifically for mass timber and heavy timber work - the SDCFC is designed for demanding applications involving large structural members such as glulam, cross-laminated timber, and multi-ply engineered wood, where a standard wood screw would fall short
• No predrilling needed in most applications - the SawTooth point reduces installation torque enough that predrilling is unnecessary in typical scenarios, cutting labor time and keeping the job moving on timber framing and beam fastening projects
• Meets CSA O86:24 hydrogen embrittlement requirements - the combination of the optimized hardness profile and the nonmetallic e-coat finish reduces the risk of brittle fracture, which is a critical consideration for long-term structural performance in engineered wood construction
• Clean aesthetic for exposed or countersunk installations - the cylinder head and black e-coat finish mean this screw looks intentional whether driven flush on an exposed beam connection or countersunk into a finished timber surface

Specifications

• Brand: Simpson Strong-Tie
• Product Name: Strong-Drive SDCFC TIMBER-CFC Screw
• Overall Length: 4-3/4 in.
• Thread Length: 4-1/4 in.
• Shank Diameter: 0.230 in.
• Head Diameter: 0.400 in.
• Head Type: Cylinder Head
• Drive Type: T40 6-Lobe
• Point Type: SawTooth Point
• Coating: E-coat Electrocoating
• Finish: E-coat Electrocoating
• Color: Black