Simpson Strong-Drive SDCFC TIMBER-CFC Screw - 0.390 in. x 39 3/8 in., T50 6-Lobe, E-Coat, 50-Pack by Simpson Strong-Tie is a heavy-duty structural wood screw engineered for demanding large-member timber applications, including mass timber, cross-laminated timber, glulam, and engineered wood assemblies. At nearly 40 inches in length with a fully threaded shank, this fastener delivers exceptional withdrawal resistance in wood-to-wood connections where conventional screws fall short. The black e-coat electrocoating finish provides a clean, finished appearance whether the screw is left exposed or countersunk - making it a practical choice for both structural integrity and visual consistency in interior dry-service timber framing projects.

Key Features

• Compact cylinder head - helps countersink the screw flush for a clean, concealed or exposed finish on heavy timber and mass timber connections
• Heavy-duty, fully threaded shank spanning 38 3/8 in. of thread length - maximizes withdrawal resistance throughout the entire fastener for superior holding power in large structural members
• SawTooth point design - enables fast starts and easy driving, reducing installation torque and eliminating the need for predrilling in most timber applications
• Black e-coat electrocoating finish - provides a construction-durable nonmetallic coating for corrosion resistance in interior dry-service conditions while delivering a consistent, aesthetically clean appearance
• Deep T50 6-lobe recess - creates a secure, slip-resistant drive engagement, reducing cam-out risk during installation of these long, high-torque fasteners
• Compliant with CSA O86:24 hydrogen embrittlement requirements - the optimized hardness profile helps mitigate risk of brittle fracture for reliable, long-term structural performance
• 0.390 in. head diameter (0.528 in. assembled head) with a 0.290 in. shank diameter - engineered proportions that balance strength, driveability, and a tidy finished profile
• Packaged 50 per box - provides a practical quantity for beam reinforcement and multi-ply fastening jobs requiring multiple full-length structural screws

Why This Product

• Designed specifically for mass timber and heavy timber structures - at 39 3/8 in. long with a fully threaded 38 3/8 in. thread, this screw reaches deep into glulam, cross-laminated timber, and engineered wood multi-ply assemblies where shorter fasteners cannot provide adequate connection strength.
• No predrilling required in most applications - the SawTooth point reduces installation torque and simplifies the fastening process for contractors working on timber framing, butt joist connections, and wall-to-wall assemblies, saving time and labor on large jobs.
• Optimized for long-term interior structural use - the black e-coat electrocoating finish combined with a carefully controlled hardness profile addresses both corrosion resistance in dry-service environments and the risk of hydrogen embrittlement, meeting CSA O86:24 requirements for structural confidence.
• Versatile across a wide range of structural connections - from fastening Simpson Strong-Tie connectors to reinforcing support beams and engineered wood multi-ply members, this single screw covers a broad scope of heavy timber and mass timber fastening tasks.

Specifications

• Brand: Simpson Strong-Tie
• Model Number: SDCFC10X1000
• Product Name: Strong-Drive SDCFC TIMBER-CFC Screw
• Length: 39 3/8 in.
• Thread Length: 38 3/8 in.
• Shank Diameter: 0.290 in.
• Head Diameter: 0.528 in.
• Head Type: Cylinder Head
• Drive Type: T50 6-Lobe
• Point Type: SawTooth Point
• Coating: E-coat Electrocoating
• Finish: E-coat Electrocoating
• Color: Black