The Simpson Strong-Drive SDCP Timber-CP Screw is a heavy-duty structural fastener engineered specifically for cross-laminated timber (CLT) and mass-timber construction, as well as general interior and dry-service applications. Featuring a partially threaded shank design, this 0.390 x 14-inch screw pulls structural members together with superb holding power and excellent load capacity - making it a trusted choice for demanding timber framing, panel connections, and interior structural assemblies. The yellow-zinc coated finish provides a durable surface that stands up to handling and installation, while the Type-17 point and T40 6-lobe drive deliver reliable engagement and reduced cam-out during fastening.

Key Features

• Flat Head with Underhead Nibs - seats cleanly flush with the timber surface for a professional, countersunk finish without additional prep work
• Partially Threaded Shank (3-1/8 in. thread length) - draws structural members tightly together by allowing the unthreaded shank to pass freely through the top member, maximizing clamping force
• Type-17 Point - self-tapping tip bores into timber without predrilling in most applications, saving time and simplifying installation
• T40 6-Lobe Drive - transfers higher torque than standard drive types, reducing bit slip and cam-out for cleaner, faster driving in dense timber
• Yellow-Zinc Coated Finish - provides corrosion resistance during storage and installation in interior and dry-service environments
• 0.700 in. Head Diameter - large bearing surface distributes load effectively over the timber face, supporting excellent holding strength
• 0.275 in. Shank Diameter - heavy-gauge shank delivers structural-grade shear and withdrawal capacity suited for mass-timber assemblies

Why This Product

• Designed specifically for cross-laminated timber and mass-timber construction - this screw addresses the unique demands of CLT panel connections, surface splines, and heavy timber framing where standard fasteners fall short on load capacity
• Predrilling is not typically required - the Type-17 point allows direct installation into timber members, cutting labor time on large-scale structural projects
• The flat head with nibs countersinks cleanly and flush - ideal for applications where surface quality matters, such as panel-to-beam and panel-to-wall connections in finished timber assemblies
• Broad length range within the SDCP product line means this screw fits into a well-established structural fastener system with proven performance in both general interior framing and specialized mass-timber applications

Specifications

• Brand: Simpson Strong-Tie
• Length: 14 in.
• Shank Diameter: 0.275 in.
• Head Diameter: 0.700 in.
• Thread Length: 3-1/8 in.
• Head Type: Flat Head with Nibs
• Drive Type: T40 6-Lobe
• Point Type: Type-17 Point
• Finish: Yellow-Zinc Coated
• Coating: Yellow-Zinc Coated
• Country of Origin: Taiwan

Available Pack Options

• SDCP271400-R25: 25 Pk - includes (1) T40, 6-lobe drive bit (replacement bit: BIT40T-134-R2)
• SDCP271400: 150 Pk - includes (1) T40, 6-lobe drive bit (replacement bit: BIT40T-134-R2)

Frequently Asked Questions

Is predrilling required before installing these screws into timber?

Predrilling is not typically required. The Type-17 point is a self-tapping design that bores directly into timber members, allowing for straightforward installation in most cross-laminated timber and mass-timber applications.

What drive bit is needed, and is one included?

These screws use a T40 6-lobe drive. A T40 6-lobe drive bit is included with your order. If you need a replacement bit in the future, the compatible part is BIT40T-134-R2.

Are these screws suitable for outdoor or wet-exposure applications?

The Strong-Drive SDCP Timber-CP screw is designed for interior and dry-service applications. It is not rated for exterior or wet-exposure conditions. The yellow-zinc coated finish is appropriate for indoor structural use.

What is the difference between the shank diameter and the overall screw size designation?

The screw is identified by its nominal size (0.390) and length (14 in.). The actual shank diameter is 0.275 in., while the head diameter is 0.700 in. The partially threaded shank covers a thread length of 3-1/8 in., with the remainder of the shank left unthreaded to allow structural members to be drawn tightly together.

Note: Product dimensions and/or thread length may differ from picture. Please see item description for specifications.