The Simpson Strong-Drive SDWH Timber-Hex Hot-Dip Galvanized Screw is a heavy-duty 0.276" diameter, 6" structural fastener engineered for demanding marine and coastal environments. Built with a Class C hot-dip galvanized coating, this screw delivers exceptional corrosion resistance in saltwater-exposed settings such as structural pilings, piers, docks, and boardwalks - eliminating the need for costly bolt-and-washer assemblies and dramatically reducing installation time on pile connections.

Key Features

• Hot-Dip Galvanized, Class C coating - provides robust corrosion protection suited for marine, coastal, and other highly corrosive outdoor environments where moisture and salt exposure are constant concerns
• SawTooth point - self-starts into heavy timber without predrilling, saving time and eliminating the cost of specialty auger drill bits on the job site
• Large Hex Washer Head (0.930" diameter) - the oversized integral washer head bears load across a wide surface area, removing the need for separate washers and simplifying the installation process
• Serrated threads with 5 TPI and 3" thread length - aggressive thread geometry bites into dense structural timber for a strong, secure grip in wood-to-wood and engineered wood pile connections
• 3/8 in. Hex drive - compatible with standard impact drivers and low-speed corded drills, allowing fast one-sided installation without the need to access the back of the connection
• 0.276" shank diameter at 6" length - sized for structural pile and heavy timber applications, delivering the holding strength needed to replace traditional 5/8" or 3/4" HDG bolt-washer-nut assemblies
• No predrilling required - the SawTooth point drives directly into timber, cutting installation time and lowering the total installed cost compared to conventional bolted pile solutions

Why This Product

• Designed specifically for structural pilings, docks, piers, and boardwalks - this screw handles the harshest marine and coastal conditions where standard fasteners corrode and fail prematurely, thanks to its Class C hot-dip galvanized finish
• Replaces multi-piece bolt, washer, and nut assemblies with a single fastener installed from one side only - eliminating extra hardware costs and the need for two workers on opposite sides of a pile connection
• No predrilling and no separate washers or nuts required - the SawTooth point and integral washer head combine to offer one of the lowest installed-cost solutions available for comparable pile and dock fastening applications
• The 3/8 in. hex drive works with a standard low-speed corded drill - no specialized tooling beyond what most crews already carry, keeping setup simple and installation fast in the field

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter (in.): 0.276
• Length (in.): 6
• Head Type: Large Hex Washer Head
• Head Diameter (in.): 0.930
• Drive Type: 3/8 in. Hex
• Thread Type: Serrated Threads
• Thread Length (in.): 3
• TPI: 5
• Point Type: SawTooth Point
• Coating: Hot-Dip Galvanized, Class C
• Country of Origin: Taiwan

Available Pack Options

• SDWH27600G-RP1: 1 Ea
• SDWH27600GR30: 30 Pk - includes (1) driver bit
• SDWH27600GMB: 150 Pk - includes (2) driver bits
• SDWH27600G: 300 Pk - includes (2) driver bits

Approved Applications

• Structural pilings, piers, docks, and boardwalks in marine and coastal environments
• Structural wood-to-wood connections in heavy timber framing
• Engineered wood connections, including ledgers and pile connections
• Replacement for HDG bolt, washer, and nut assemblies in pile applications

Install With

• For best results, use a minimum of 1/2 in. low-speed corded drill to install

Frequently Asked Questions

Do I need to predrill before installing this screw into timber?

No predrilling is required. The SawTooth point is designed to self-start directly into structural timber, saving installation time and eliminating the need for specialty auger drill bits.

What type of drive tool is recommended for this screw?

A minimum of a 1/2 in. low-speed corded drill is recommended for best results. The screw uses a 3/8 in. Hex drive, which is compatible with standard hex-drive sockets and bits.

Why does this screw use a Large Hex Washer Head with a 0.930" diameter head?

The oversized integral washer head distributes bearing load across a wider surface area on structural timber connections. This eliminates the need to purchase and install separate washers, reducing hardware costs and speeding up the installation process.

Is this screw suitable for saltwater and coastal environments?

Yes. This screw features a Hot-Dip Galvanized, Class C coating, which is specifically suited for heavy-duty marine and coastal applications including structural pilings, piers, docks, and boardwalks where exposure to moisture and corrosive elements is a primary concern.