Simpson Strong-Tie #10 x 3-1/2" Bugle-Head Wood Screw in Type 305 Stainless Steel is engineered for professional-grade fastening of all types of wood decking, including cedar, redwood, and preservative-treated lumber. With a 6-lobe T25 drive, Type-17 point, and flush-countersinking bugle head, this corrosion-resistant deck screw delivers a clean, concealed finish while standing up to demanding outdoor and wet-environment applications.

Key Features

• Type 305 Stainless Steel material - provides superior corrosion resistance, making these screws well-suited for cedar, redwood, and chemically treated wood decking exposed to moisture and outdoor conditions.
• 6-Lobe T25 drive recess - delivers a secure bit engagement that significantly reduces cam-outs during installation and extends bit life, saving time and reducing tool wear on long decking projects.
• Bugle head design engineered for flush countersinking - seats cleanly at the wood surface without cracking or mushrooming the decking, resulting in a more concealed, professional-looking finish.
• Type-17 point - cuts into wood fibers quickly for fast starts and easier driving, reducing the need for pre-drilling in most applications and speeding up installation.
• Coarse thread pattern - pulls decking boards and other material tightly to the framing for a snug, secure connection that resists loosening over time.
• #10 screw diameter with 0.340" head diameter - sized to provide strong holding power in standard wood decking while keeping the fastener profile low and discreet at the surface.
• Approximately 56 screws per pound - helps contractors and DIYers estimate quantities accurately before starting a project, reducing waste and over-ordering.

Why This Product

• For decking projects exposed to rain, humidity, or coastal environments, Type 305 Stainless Steel construction resists rust and corrosion far better than standard steel or zinc-plated alternatives - making this screw a reliable long-term choice for outdoor wood surfaces.
• The 6-lobe T25 drive system reduces the frustration and material damage caused by cam-outs, giving installers greater control during driving and a cleaner result on finished decking surfaces.
• The bugle head geometry works with the wood surface rather than against it - countersinking flush without splitting or raising the grain, which is especially valuable when working with softer species like cedar and redwood.
• With compatibility across cedar, redwood, and preservative-treated non-hardwood decking materials, this single screw size covers a wide range of common residential and light commercial decking applications.

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #10
• Length: 3-1/2 in.
• Head Type: Bugle Head
• Head Diameter: 0.340 in.
• Drive Type: T25 6-Lobe
• Thread Type: Coarse Threads
• Point Type: Type-17 Point
• Material: Type 305 Stainless Steel
• Finish: Type 305 Stainless Steel
• Approx. Count Per Lb: 56
• Country of Origin: Taiwan

Available Pack Options

• S10350DT1: 1 Lb (56) - includes (1) T25 6-lobe driver bit
• S10350DT5: 5 Lb (280) - includes (1) T25 6-lobe driver bit
• S10350DTB: 1000 Pk - includes (2) T25 6-lobe driver bits

Frequently Asked Questions

What types of wood decking are these screws compatible with?

These screws are compatible with all types of wood decking, including cedar, redwood, and preservative-treated woods. They are not intended for hardwood decking applications.

Why is the 6-lobe T25 drive better than a standard Phillips drive for deck screws?

The 6-lobe drive recess provides a more secure engagement between the bit and the screw head, which reduces cam-outs during driving. This means less slipping, less damage to the screw head and surrounding wood surface, and longer usable life for the driver bit.

Do I need to pre-drill before installing these screws?

The Type-17 point is designed for fast starts and efficient penetration into wood, reducing the need for pre-drilling in most situations. However, pre-drilling is recommended near board ends to help prevent splitting.

Why choose Type 305 Stainless Steel for outdoor or treated-lumber applications?

Type 305 Stainless Steel offers superior corrosion resistance compared to standard steel fasteners, making it well-suited for exterior decking environments where exposure to moisture, humidity, and preservative-treated wood chemicals is a concern. This material helps the screws maintain their integrity and appearance over time in demanding outdoor conditions.

Note: Product dimensions may differ from picture.