The Simpson Strong-Drive SDCF TIMBER-CF Screw is a heavy-duty structural fastener engineered specifically for cross-laminated timber (CLT) construction, mass timber assemblies, and general interior wood-to-wood connections. Built with a 0.390-inch major diameter and a fully-threaded shank, this screw delivers the high withdrawal resistance demanded by structural timber applications - making it a trusted choice for beam reinforcement, wall-to-wall fastening, and butt joist connections. The yellow-zinc coating provides corrosion resistance suitable for interior and dry-environment use, while the proprietary point geometry ensures fast starts and clean penetration even in dense timber materials.

Key Features

• Flat head with underhead nibs - helps the screw countersink cleanly and flush into timber surfaces, eliminating the need for pre-drilling a countersink and producing a finished appearance in exposed mass timber applications.
• Fully-threaded 0.290-inch shank with 9-1/8-inch thread length - maximizes thread engagement along the full depth of the connection, delivering superb withdrawal resistance in demanding structural timber assemblies.
• 0.390-inch major diameter - provides the heavy-duty structural capacity needed for cross-laminated timber and mass timber construction where standard fasteners are insufficient.
• Proprietary unique point design - enables fast starts and reduces splitting in dense timber, speeding up installation without sacrificing holding power.
• Deep T50 6-lobe drive recess - transfers high torque to the fastener with less cam-out risk, so installers maintain control during high-torque structural driving (compatible replacement bit: BIT50T-2-R1).
• Head stamp with length in millimeters - simplifies field inspection and compliance verification by allowing inspectors to confirm fastener length visually without additional measuring.
• Interior-grade yellow-zinc coating - protects the fastener from corrosion in dry, interior environments including mass timber buildings and CLT panel systems.
• Includes two T50 6-lobe driver bits - gets the job started immediately out of the box, with compatible replacement bits (BIT50T-2-R1) available separately for continued use.

Why This Product

• Purpose-built for mass timber and CLT construction - the SDCF TIMBER-CF screw is designed from the ground up for cross-laminated timber and mass timber applications, where connection geometry, withdrawal resistance, and flush installation are all critical performance factors.
• High withdrawal resistance without pre-drilling - the fully-threaded shaft and proprietary point geometry work together to achieve structural holding power in dense timber members, reducing prep time while meeting demanding load requirements.
• Clean, inspectable installations - the countersinking flat head with nibs produces a flush surface finish, and the millimeter-stamped head simplifies third-party inspection - a practical advantage in engineered timber projects with oversight requirements.
• Trusted Simpson Strong-Tie structural engineering - manufactured by Simpson, a recognized name in structural connectors and fasteners, this screw is designed to meet the performance standards expected in beam reinforcement, wall-to-wall connections, and support beam fastening.

Specifications

• Brand: Simpson Strong-Tie
• Coating: Yellow-Zinc Coated
• Finish: Yellow-Zinc Coated
• Drive Type: T50 6-Lobe
• Head Type: Flat Head with Nibs
• Head Diameter: 0.725 in.
• Shank Diameter: 0.290 in.
• Major Diameter: 0.390 in.
• Length: 9-1/2 in. (240 mm)
• Thread Length: 9-1/8 in.
• Country of Origin: Austria

Available Pack Options

• SDCF27912-R30: 30 Pk
• SDCF27912: 250 Pk - includes two T50, 6-lobe driver bits (replacement bit: BIT50T-2-R1)

Approved Applications

• Beam Reinforcement
• Fastening Wall-to-Wall
• Fastening Butt Joists
• Mass Timber / Cross-Laminated Timber (CLT)
• Fastening Support Beams

Frequently Asked Questions

Is this screw suitable for outdoor or pressure-treated lumber applications?

No. The SDCF TIMBER-CF screw features an interior-grade yellow-zinc coating and is designed for interior and dry applications only. It is not recommended for outdoor exposure, high-humidity environments, or use with pressure-treated lumber where a more robust corrosion-resistant coating would be required.

What driver bit does this screw require, and what is the replacement bit part number?

This screw requires a T50 6-lobe (Torx-style) driver bit. Two T50 6-lobe driver bits are included in the package. The compatible replacement bit is the BIT50T-2-R1, available separately for continued use on the job site.

Why is this screw fully threaded, and how does that benefit structural timber connections?

The fully-threaded shank - with a thread length of 9-1/8 inches - maximizes thread engagement throughout the entire depth of the connection. This design provides superior withdrawal resistance compared to a partially-threaded fastener, which is critical in structural applications such as cross-laminated timber panels, mass timber beam connections, and wall-to-wall fastening.

What does the head stamp on the screw indicate?

Each screw head is stamped with the fastener length expressed in millimeters. This allows field inspectors and project managers to verify the correct fastener length has been installed without needing a separate measuring tool - a practical feature for engineered timber projects that require fastener compliance documentation.