The Simpson Strong-Drive SDCF Timber-CF Screw in 0.390 x 7-7/8" is a redesigned structural fastener from Simpson engineered specifically for cross-laminated timber (CLT), mass timber construction, and general interior applications. Built for heavy timber and engineered wood assemblies, this black e-coat screw delivers flush, clean installation with the torque-reducing performance that demanding structural work requires. Whether you're fastening glulam beams, reinforcing surface splines, or securing multi-ply engineered wood panels, this timber screw provides the strength and finish quality professionals expect.

Key Features

• Flat Head with Underhead Nibs - enables clean countersinking into CLT and mass timber surfaces, resulting in a flush finish without additional prep work
• SawTooth Point - ensures fast starts and reduces installation torque, eliminating the need for predrilling in most timber applications to speed up workflow
• T50 6-Lobe Drive Type - provides high-torque transfer with reduced cam-out risk, giving the installer greater control during heavy timber fastening
• Black E-Coat Electrocoating Finish - enhances aesthetics for exposed interior timber applications while contributing to a cleaner, more professional appearance
• Optimized Hardness Profile - works alongside the e-coat finish to help mitigate the risk of brittle fracture, supporting reliable long-term structural performance
• 0.290" Shank Diameter with 7-5/8" Thread Length - maximizes thread engagement through thick timber members, contributing to strong, secure wood-to-wood and wood-to-steel connections
• 0.725" Head Diameter - the wide flat head distributes load effectively across timber surfaces, reducing the chance of pull-through in demanding structural joints

Why This Product

• Designed specifically for CLT and mass timber construction - the SawTooth point and optimized thread geometry mean you can drive into dense laminated timber without predrilling in most cases, saving time on large-scale timber framing projects
• The black e-coat finish makes this screw well-suited for exposed interior mass timber applications where fastener appearance matters alongside structural function
• The optimized hardness profile directly addresses the brittle fracture risk common in high-strength structural screws, making it a more dependable long-term choice for beam reinforcement, glulam assemblies, and multi-ply fastening
• Versatile enough for wood-to-wood, wood-to-steel, and Simpson Strong-Tie connector fastening - one screw covers a wide range of structural connection types found in timber framing and heavy timber projects

Specifications

• Brand: Simpson Strong-Tie
• Length: 7-7/8 in.
• Shank Diameter: 0.290 in.
• Head Diameter: 0.725 in.
• Thread Length: 7-5/8 in.
• Head Type: Flat Head with Nibs
• Drive Type: T50 6-Lobe
• Point Type: SawTooth Point
• Coating: E-coat Electrocoating
• Finish: E-coat Electrocoating
• Color: Black
• Country of Origin: Taiwan

Available Pack Options

• SDCF10X200-R30: 30 Pk - includes T50, 6-lobe driver bit (replacement bit: BIT50T-2-R1)
• SDCF10X200-R30 -6: 180 Pk - includes T50, 6-lobe driver bit (replacement bit: BIT50T-2-R1)
• SDCF10X200: 250 Pk - includes T50, 6-lobe driver bit (replacement bit: BIT50T-2-R1)

Approved Applications

• Mass Timber / Cross-Laminated Timber (CLT)
• Heavy Timber
• Timber Framing
• Glulam
• Engineered Wood - Multi-Ply Fastening
• Engineered Wood
• Beam Reinforcement
• Surface Splines
• Fastening Wood-to-Wood
• Fastening Wood-to-Steel
• Fastening Support Beams
• Fastening Simpson Strong-Tie Connectors
• Fastening Wall-to-Wall
• Fastening Floor-to-Floor
• Fastening Butt Joists
• Fastening Stud-to-Plate
• General Interior

Frequently Asked Questions

Does this screw require predrilling before installation?

In most applications, predrilling is not required. The SawTooth point is specifically designed to ensure fast starts and reduce installation torque, allowing the screw to be driven directly into CLT, mass timber, glulam, and other engineered wood without predrilling under typical conditions.

What drive bit does this screw use, and is one included?

This screw uses a T50 6-lobe drive bit. A T50 6-lobe driver bit is included with this product. If you need a replacement bit, the compatible replacement is the BIT50T-2-R1.

Why does this screw have an e-coat finish instead of a standard zinc coating?

The black e-coat electrocoating finish serves two purposes: it enhances the appearance of the fastener for exposed interior mass timber and CLT applications, and together with the optimized hardness profile, it helps mitigate the risk of brittle fracture - a key durability consideration in structural screws used for heavy timber and beam reinforcement.

What types of connections is this screw rated for?

The SDCF Timber-CF screw is approved for a wide range of structural connections including wood-to-wood, wood-to-steel, fastening Simpson Strong-Tie connectors, multi-ply engineered wood fastening, glulam assemblies, surface splines, beam reinforcement, stud-to-plate, wall-to-wall, and floor-to-floor connections, as well as general interior applications.