Simpson Deck-Drive DCU Composite Screw in #10 x 2-3/4" with Type 305 Stainless Steel finish is purpose-built for fastening composite and PVC deck boards, delivering corrosion resistance and a clean, concealed appearance in one engineered fastener. Designed by Simpson, this deck screw combines a Type-17 point for clean penetration, inverted upper threads that clear excess material, and a color-matching painted cap head in Gray 04 - making it an ideal choice for professional deck installations and DIY composite decking projects alike. The Type 305 stainless steel construction is especially well-suited for outdoor environments with exposure to chlorides, salt air, or moisture, where long-term corrosion protection is critical.

Key Features

• Type 305 Stainless Steel material - provides robust corrosion resistance for composite and PVC decking applications, particularly in coastal or chloride-rich environments where standard fasteners fail prematurely.
• Type-17 Point - penetrates composite decking cleanly without pre-drilling, saving installation time and reducing surface damage during fastening.
• Inverted upper Tri-Lobe Threads - engineered to clear excess material away from the installation zone, resulting in a secure, flush connection and a clean finished surface.
• Cap Head with 0.230" head diameter - sits firmly against the decking surface for a secure hold while maintaining a low-profile, finished appearance.
• T20 6-Lobe drive type - delivers high torque transfer with reduced cam-out risk, making installation faster and more reliable compared to traditional Phillips-drive screws.
• Gray 04 color-matching painted head - blends with popular composite decking manufacturers' colors for a more concealed, professional finish that enhances the overall appearance of the deck surface.
• 2-3/4" length in #10 screw size - appropriately sized for composite deck board fastening, providing the holding depth needed for a secure, long-lasting installation.

Why This Product

• Eliminates the need to mix and match fasteners across different composite decking brands - the DCU is engineered for all types of composite and PVC decking, simplifying your fastener selection on the job site.
• The Type 305 stainless steel finish addresses corrosion concerns head-on, making this screw a dependable choice for decks exposed to moisture, salt spray, or chloride-heavy environments where inferior fasteners would corrode and stain the deck surface.
• The color-matching Gray 04 painted head blends with popular decking manufacturers' products, giving the finished deck a cleaner, more professional look compared to standard silver or zinc-plated screws.
• The combination of a Type-17 point and inverted upper threads means the screw drives cleanly and clears material efficiently - reducing installation effort and the likelihood of surface mushrooming or raised material around the fastener head.

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #10
• Length: 2-3/4 in.
• Head Diameter: 0.230 in.
• Head Type: Cap Head
• Drive Type: T20 6-Lobe
• Thread Type: Tri-Lobe Threads
• Point Type: Type-17 Point
• Material: Type 305 Stainless Steel
• Finish: Type 305 Stainless Steel
• Color: Gray 04

Available Pack Options

• DCU234P305GR04: 350 Pk - includes 1 driver bit included
• DCU234MB305GR04: 1750 Pk - includes 2 driver bits included

Approved Applications

• Decks - Deck Boards Composite

Frequently Asked Questions

What type of decking material is the Deck-Drive DCU Composite Screw designed for?

The DCU Composite Screw is engineered for all types of composite and PVC decking. Its Type-17 point and Tri-Lobe threads are specifically designed to penetrate and fasten composite deck boards cleanly and securely, without the need to mix and match different fasteners for different decking brands.

Why is Type 305 Stainless Steel used for this screw, and where does it perform best?

Type 305 stainless steel provides strong corrosion resistance, making the DCU Composite Screw especially well-suited for outdoor decking environments exposed to chlorides - such as coastal locations, areas with salt air exposure, or situations involving frequent moisture contact. This material helps ensure the fastener maintains its integrity and appearance over time in demanding conditions.

What drive bit is compatible with the Deck-Drive DCU Composite Screw?

The DCU Composite Screw uses a T20 6-Lobe drive type. A compatible replacement driver bit is the BIT20T-2-R2, which is designed to work with this screw for efficient, low-cam-out installation.

How does the inverted upper thread design benefit the installation process?

The inverted upper Tri-Lobe Threads on the DCU Composite Screw are engineered to clear excess composite material away from the fastener hole as the screw is driven. This prevents material from piling up or mushrooming around the screw head, resulting in a clean, flush, and secure installation with a more finished appearance at the deck surface.

Downloads and Resources

• Composite-Decking Color Cross-Reference chart

Related Products

• - Compatible T20 6-Lobe driver bit
• Deck-Drive Screw Plug Solution - Color-matching DCU Screw Plugs compatible with these fasteners