The Simpson Strong-Drive SDCP Timber-CP Screw with T40 6-Lobe drive and yellow-zinc coating is a structural fastener engineered for cross-laminated timber construction, mass timber construction, and general interior applications. Built by Simpson, this partially-threaded screw pulls structural members together with superb holding power, making it a dependable choice for heavy timber framing, panel-to-beam connections, and lap joints where a clean, countersunk finish is required.

Key Features

• Yellow-Zinc Coated Finish - provides a corrosion-resistant barrier suited for interior structural applications, helping preserve long-term fastener integrity in mass timber assemblies
• 0.390 in. Overall Diameter with 0.275 in. Shank - the robust shank diameter delivers the structural rigidity needed to resist withdrawal and shear forces in timber connections
• 6-1/4 in. Length with 3-1/8 in. Thread Length (Partial Thread) - the partially-threaded design draws mating members tightly together, creating a firm clamping action that solid-thread fasteners cannot achieve in the same way
• Flat Head with Underhead Nibs and 0.7 in. Head Diameter - the wide flat head provides clean, flush countersinking without pre-drilling, while the nibs seat the fastener securely and prevent spin-out
• T40 6-Lobe Drive Type - the high-torque Torx-style drive reduces cam-out during installation, allowing full torque transfer and faster, more controlled driving even in dense timber
• Type-17 Point - the self-tapping point bores into wood fibers cleanly, reducing the need for pre-drilling and saving significant time on the job site

Why This Product

• Designed specifically for cross-laminated timber and mass timber construction - this screw addresses the unique demands of engineered wood assemblies where precise clamping force and structural performance are critical
• The partially-threaded configuration actively pulls members together as the screw is driven, eliminating gaps between panels, beams, and walls that can compromise structural integrity
• The T40 6-Lobe drive combined with the Type-17 point means faster installation without cam-out or pre-drilling in most interior timber applications, reducing labor time on large-scale framing projects
• The large flat head with underhead nibs delivers a clean, countersunk finish on visible timber surfaces - ideal for applications like surface splines and ledger connections where appearance and flush seating both matter

Specifications

• Brand: Simpson Strong-Tie
• Overall Diameter: 0.390 in.
• Length: 6-1/4 in.
• Shank Diameter: 0.275 in.
• Head Diameter: 0.7 in.
• Thread Length: 3-1/8 in.
• Drive Type: T40 6-Lobe
• Head Type: Flat Head with Nibs
• Point Type: Type-17 Point
• Finish: Yellow-Zinc Coated
• Thread Style: Partial Thread
• Measurement Unit: Pack

Available Pack Options

• SDCP27614-R30: 30 Pk
• SDCP27614: 250 Pk

Approved Applications

• Cross-laminated timber (CLT) construction
• Mass timber construction
• General interior structural applications
• Wall to wall connections
• Floor to floor connections
• Wall to floor connections
• Panel to beam connections
• Panel to wall connections
• Surface splines
• Lap joints
• Ledger connections
• General timber framing

Frequently Asked Questions

What type of drive tool is required for this screw?

This screw uses a T40 6-Lobe (Torx-style) drive, so a T40 driver bit is required for installation. The 6-lobe profile maximizes torque transfer and minimizes cam-out, making it well-suited for driving into dense structural timber.

Does this screw require pre-drilling before installation?

The Type-17 point is a self-tapping design that bores into wood fibers on contact, which typically eliminates the need for pre-drilling in most interior timber applications. This helps speed up installation on mass timber and cross-laminated timber projects.

Why is a partially-threaded screw preferred for timber-to-timber connections?

The partial thread - 3-1/8 in. of thread on a 6-1/4 in. screw - means the unthreaded shank slides freely through the first member while the threaded tip grips the second. This creates a clamping force that actively draws the two members tightly together, closing gaps that a fully-threaded fastener would not close in the same way.

What does the yellow-zinc coating provide for this fastener?

The yellow-zinc coating offers a corrosion-resistant surface treatment appropriate for interior structural applications, including general timber framing and mass timber assemblies. It is not intended as a substitute for hot-dip galvanized or stainless finishes in exterior or high-moisture environments.

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