Simpson Strong-Drive SDWH TIMBER-HEX Stainless Steel Screw - 0.185" x 8" is a Type 316 stainless steel structural fastener engineered as a direct replacement for traditional lag screws in wood-framing applications. Built with a 5/16 in. hex washer head and a sharp point that eliminates the need for predrilling, this heavy-duty timber screw delivers faster, easier installation without sacrificing structural integrity. The Type 316 stainless steel construction provides exceptional resistance to corrosion, making it well suited for outdoor, coastal, and chemically exposed environments where standard fasteners would deteriorate. These structural wood screws meet 2018 and 2021 IRC and IBC code requirements for several common wood-framing applications, giving contractors and builders the confidence of code-compliant connections.

Key Features

• Type 316 stainless steel material and finish - delivers maximum corrosion protection in saltwater, coastal, chemical, and harsh outdoor environments where lesser finishes would fail over time.
• No predrilling required in most applications - the sharp point drives directly into wood, reducing labor time and eliminating the extra step of pilot holes compared to standard lag screws.
• 5/16 in. hex drive with hex washer head - the large bearing surface distributes load across the connection, and the hex drive allows use with standard impact drivers and drill drivers for efficient installation.
• Unique box thread design - the raised-ridge box thread technology significantly reduces driving torque, making installation less fatiguing and faster in dense timber framing applications.
• 8 in. length with 2-3/8 in. thread length and 0.185 in. shank diameter - sized for substantial timber connections where a true lag-screw replacement is required for structural load transfer.
• Meets 2018 and 2021 IRC and IBC code requirements - suitable for several common wood-framing applications, supporting code-compliant structural assemblies without additional engineering in covered scenarios.
• Driver bit included - the included 5/16 in. driver bit means you can begin installation immediately without a separate trip to source accessories.

Why This Product

• True lag-screw replacement without the predrilling hassle - traditional lag screws demand pilot holes before driving, adding time and tooling to every connection. This hex-head timber screw's sharp point penetrates wood directly, streamlining the workflow on structural framing jobs.
• Built for long-term performance in corrosive conditions - Type 316 stainless steel goes beyond standard galvanized or coated fasteners, offering the level of corrosion resistance needed in marine environments, pressure-treated lumber, and outdoor decking or ledger applications where moisture and chemicals are constant factors.
• Code acceptance removes guesswork on the job site - compliance with both 2018 and 2021 IRC and IBC requirements means these structural wood screws are ready for inspected residential and commercial framing applications without custom engineering approvals in covered use cases.
• Reduced driving torque means faster, less fatiguing installation - the box thread geometry with raised-ridge technology lowers the resistance felt during driving, which is especially valuable when setting a large number of fasteners in a single framing session.

Specifications

• Brand: Simpson Strong-Tie
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Length: 8 in.
• Shank Diameter: 0.185 in.
• Head Diameter: 0.455 in.
• Thread Length: 2 3/8 in.
• Thread Type: Box Threads
• Head Type: Hex Washer Head
• Drive Type: 5/16 in. Hex
• Point Type: Sharp Point
• Country of Origin: Taiwan

Available Pack Options

• SDWH19800SS-R10: 10 Pk - includes (1) driver bit
• SDWH19800SS-R50: 50 Pk - includes (1) driver bit

Frequently Asked Questions

Can this screw be used without predrilling?

Yes. The sharp point tip is designed to penetrate wood directly, so predrilling is not required in most applications. This is one of the key advantages over traditional lag screws, which typically require a pilot hole before installation.

Is this fastener suitable for outdoor and coastal environments?

Yes. The screw is made from Type 316 stainless steel, which provides maximum corrosion resistance and is well suited for outdoor, coastal, saltwater, and chemically exposed environments where galvanized or lower-grade stainless fasteners may not hold up long term.

Does this screw meet current building code requirements?

Yes. The Simpson Strong-Drive SDWH TIMBER-HEX SS screw meets 2018 and 2021 IRC and IBC code requirements for several common wood-framing applications, supporting inspected residential and commercial structural connections in covered use cases.

What tool is needed to drive this screw?

The screw uses a 5/16 in. hex drive, compatible with standard impact drivers and drill drivers fitted with a hex socket or hex bit. A driver bit is physically included with the product so you can begin installation right away.

Note: Product dimensions and/or thread length may differ from picture.