Key Features

Built for Salt Air Type 316 stainless steel gives this screw the corrosion resistance needed for coastal and marine wood connections where standard structural fasteners can be the weak link. Fast Structural Install The SawTooth point starts quickly and usually eliminates predrilling and counterboring, so you move faster on heavy wood-to-wood fastening jobs. Heavy-Duty Timber Screw With a 0.275 inch shank and large washer head, the Simpson Strong-Tie SDWS27800SS timber screw is made for serious structural wood connections, not light trim work.

Overview

The Simpson Strong-Tie SDWS27800SS Strong-Drive SDWS Timber Screw is a structural wood screw for heavy-duty wood-to-wood fastening in harsh outdoor environments. This is a timber screw designed for structural wood-to-wood connections in coastal, marine, and other severe corrosion applications. Model Number: SDWS27800SS. If you are building or repairing piers, boardwalks, wharves, ledgers, or other exposed timber assemblies, this screw is made for that kind of work.

What matters most here is the combination of installation speed and structural intent. The 0.275 inch shank diameter puts this fastener in the heavy-duty category, giving it the strength expected for timber connections where spikes, lag bolts, or lag screws are commonly used. Simpson positions it as an easier-to-install alternative to through-bolting and traditional lag screws, which matters when you are driving a lot of fasteners into dense framing or large treated members and want to avoid extra setup time.

The SawTooth point is there for a reason. It helps the screw start fast and reduces the need for predrilling in most applications, which saves time on site and cuts down on bit changes. The mid-shaft knurl also helps reduce driving torque, so the screw drives more efficiently into wood. On jobs where you are fastening ledger material, heavy planks, or structural members one after another, that translates into quicker installation and less fighting the fastener.

The head and drive design are equally practical. The large 0.650 inch washer head provides a broad bearing surface, which helps clamp material effectively and seat flush to the surface. Nibs under the head help reduce splintering as the head pulls down. The deep T50 6-lobe recess is built for a more secure drive with fewer cam-outs than shallow recess designs. On structural screws this size, drive engagement matters because stripped heads waste time and make removal a headache.

Material selection is a major reason to buy this version. SDWS27800SS is made from Type 316 stainless steel, which is the right call when the connection will see salt air, coastal moisture, or generally aggressive corrosion exposure. That makes it a much better fit for boardwalks, piers, and oceanfront rail or deck work than standard coated carbon steel fasteners. If the environment is what usually kills the hardware first, this screw addresses that problem directly.

This specific version is 8 inches long with a 3 inch thread length and 5 threads per inch, giving you the length needed for thicker member tie-ins and larger timber work. It is a hand-drive screw with a washer head and SawTooth point, intended for fastening wood to wood and engineered wood to wood where strong hold and code-recognized performance matter. Simpson also notes that the SDWS Timber SS screw is code listed under IAPMO UES ER-192 and meets 2018 and 2021 IRC and IBC code requirements for several common wood framing and engineered-wood applications.

The pack quantity here is 200 screws, so this is not a small grab-and-go blister pack. It is aimed at builders, deck crews, marine contractors, repair crews, and serious property owners doing substantial timber work. If you need a coastal-rated structural screw that installs faster than a lag and is meant to replace more cumbersome fastening methods in many applications, this is the version to look at.

Made for Marine and Coastal Work

This is where this screw earns its keep. The Type 316 stainless steel build is meant for structures exposed to salt air and moisture where ordinary fasteners can corrode long before the lumber is done.

• Designed for coastal or severe corrosion environments
• Typical uses include piers, boardwalks, wharves, and ledgers

Drive Big Screws Without the Usual Hassle

Large structural screws only save time if they go in cleanly. The SawTooth point, mid-shaft knurl, and deep 6-lobe recess are all there to help reduce effort during install and keep the bit engaged.

• SawTooth point helps start quickly and usually avoids predrilling
• Deep T50 6-lobe recess helps limit cam-out under load

Head Design That Pulls Tight and Finishes Clean

The large washer head gives you solid bearing on the wood surface, and the nibs help the head seat flush with less surface tear-out. That matters when you want clamping force without chewing up the face of the board.

• 0.650 inch head diameter increases load-bearing area
• Washer head with nibs helps reduce splintering as it seats

See the Screw Geometry Up Close

This profile shot shows why the screw installs the way it does. You can clearly see the large head, heavy shank, thread section, knurled area, and aggressive point that make it a true timber fastener.

• 0.275 inch shank diameter for heavy-duty structural fastening
• 8 inch overall length with 3 inch thread length

What’s in the Box

• (200) Simpson Strong-Tie SDWS27800SS 0.275 in. x 8 in. Strong-Drive SDWS Timber SS Screws

Key Specifications

Compatibility

Drive Interface Uses a T50 6-lobe drive. Simpson lists replacement driver bit BIT50T-2-R1. Application Fit Designed for wood-to-wood and engineered-wood structural connections.

Built For

Marine Construction Deck Building General Contracting Exterior Structural Woodwork Boardwalk Repairs Pier and Wharf Work Ledger Fastening Severe Corrosion Environments

Pro Tip

On ledger or heavy timber work near board ends, pay attention to edge and end distances. Simpson notes that for screws placed between 2 and 4 inches from the end, predrilling with a 3/16 inch drill bit is required.

Tool Nut’s Take

Tool Nut’s Take

Simpson Strong-Tie SDWS27800SS Strong-Drive SDWS Timber Screw for real exterior structural work

If you need a long structural screw that can handle coastal exposure without turning into a rust problem, this is the right kind of fastener.

• Who it’s for: Contractors and serious DIYers building or repairing piers, boardwalks, ledgers, rails, and other heavy exterior wood connections.
• Why it stands out: Type 316 stainless steel, a true heavy-duty 0.275 inch shank, and a drive design that makes big screws faster to install than old-school lag hardware in many applications.
• Worth knowing: This is a 200-pack of 8 inch timber screws, so it is meant for substantial projects. Make sure you have the correct T50 6-lobe bit on hand.

Common Questions

• What material is this screw made from? It is made from Type 316 stainless steel.
• What is this screw designed to fasten? It is designed for structural wood-to-wood and engineered-wood connections.
• Does this screw usually require predrilling? Simpson states that no predrilling or counterboring is required for most applications, thanks to the SawTooth point design.
• What drive size does it use? It uses a deep T50 6-lobe recess.
• Where is this screw commonly used? Typical applications include piers, boardwalks, wharves, and ledgers in coastal or severe corrosion environments.