Description

Key Features

No Predrilling Needed

The Type-17 point starts fast and drives cleanly into wood, which helps speed up installation and reduce splitting on connector and wood-to-wood jobs.

Built for Connectors

This Simpson Strong-Tie heavy-duty connector screw is made for Simpson Strong-Tie connectors and structural fastening where holding power and consistent installation matter.

Corrosion Resistance

The double-barrier coating helps protect the screw in exterior wood applications, making it a practical pick for deck work and other exposed fastening jobs.

Overview

The Simpson Strong-Tie SDS25312MB Strong-Drive SDS Heavy-Duty Connector Screw is a 1/4 in. x 3-1/2 in. structural wood screw sold in a 125-count pack. This is a heavy-duty connector screw designed for fastening Simpson Strong-Tie connectors and for structural wood-to-wood applications where you want strong holding power without the extra step of predrilling. Model Number: SDS25312MB.

What makes this screw matter on the job is how it goes in. The Type-17 point is there to start quickly and reduce splitting, so you can move faster in framing, deck work, and connector installation. The serrated threads help the screw pull and bite into the wood instead of just forcing its way through it, which gives you a tight connection with less fuss.

This fastener uses a 3/8 in. hex drive and a hex head with an integrated 0.500 in. washer. In practical terms, that means better driver engagement, less chance of cam-out, and better bearing surface under the head. That wider bearing area helps clamp hardware and wood securely, which is exactly what you want when working with heavy-duty connectors and structural assemblies.

The 3-1/2 in. overall length and 2-1/4 in. thread length put this specific SDS25312MB in a useful middle ground for many connector and exterior wood fastening jobs. It is long enough for serious engagement in wood, but still sized for applications where you do not want to jump all the way to the longer 4-1/2 in., 5 in., or 6 in. versions in the SDS line.

For outdoor use, the double-barrier coating is one of the big reasons to choose this version. It is intended to improve corrosion resistance versus plain steel fasteners, which matters in deck framing, exterior projects, and other jobs where moisture is part of the deal. If you are matching the fastener to exterior connector work, that coating is not a throwaway spec. It is part of the reason the assembly lasts.

Simpson Strong-Tie also designed these for easy identification after installation. The head is stamped with the Simpson Strong-Tie identification mark and the fastener length, which helps when you are inspecting completed work or verifying that the right screw went into the right connector location.

Installation is straightforward, but the recommended setup matters. Simpson Strong-Tie calls for a low-speed 1/2 in. drill with a 3/8 in. hex driver. That makes sense for a fastener in this size class because controlled speed and steady torque help the screw seat cleanly without burning up the driver or overdriving the connection.

Who is this for? Contractors, deck builders, remodelers, carpenters, and serious DIY users who need a structural wood screw for connector fastening and exterior wood work. If you are installing heavy-duty Simpson Strong-Tie connectors, or you want a stronger and faster alternative to old-school lag-style installation in many wood applications, this is the kind of fastener worth buying by the box instead of by the handful.

Fast Starts Save Time

This screw is built to go in without the usual slowdown. For deck framing and other exterior wood fastening jobs, that means less time drilling pilot holes and more time actually moving the build forward.

• Type-17 point helps start the screw quickly without predrilling
• 1/4 in. diameter structural wood screw for connector and wood-to-wood applications

Made to Clamp Connectors Tight

Connector screws only matter if they seat clean and hold hard. The hex head and integrated washer give this fastener the bearing surface and drive engagement needed for structural connector work.

• 3/8 in. hex drive helps reduce driver slip under load
• Hex head with integrated washer helps spread clamping force on the connector face

Clean Look, Serious Holding Power

When you are working with exposed hardware and finished framing, a fastener that installs cleanly matters. These screws are designed for structural use, but they also leave a tidy, consistent finished connection.

• Serrated threads help pull the fastener into the wood for a firm connection
• Head stamping helps identify the installed fastener later

Exterior Ready for Everyday Jobs

The double-barrier coating makes this version a smart fit for outdoor wood projects where exposure is part of the job. It is a practical choice for exterior brackets, deck framing, and other hardware mounted to wood.

• Double-barrier coating for corrosion resistance
• Suitable for exterior wood fastening and heavy-duty Simpson Strong-Tie connectors

What’s in the Box

• (125) 1/4 in. x 3-1/2 in. Heavy-Duty Connector Screws

Driver bit is not listed as included with this SDS25312MB package.

Key Specifications

Length	3-1/2 in.
Shank Diameter	0.235 in.
Drive Type	3/8 in. Hex
Coating / Material	Double-Barrier Coating
Thread Type	Serrated Threads
Thread Length	2-1/4 in.
Point Type	Type-17 Point
Packaging Quantity	125

Compatibility

Driver Interface

Uses a 3/8 in. hex drive. Simpson Strong-Tie recommends installation with a 3/8 in. hex driver.

Replacement Bit

Replacement driver bit: BITHEXR38-R1.

Connector Use

Designed for heavy-duty Simpson Strong-Tie connectors and structural wood applications.

Built For

Deck Building Carpentry Construction Remodeling Exterior Wood Fastening Connector Installation Wood-to-Wood Fastening DIY / Hobbyist

Pro Tip

Use a low-speed 1/2 in. drill with a 3/8 in. hex driver and keep the screw running straight to the wood grain. You will get cleaner seating at the connector and better control than trying to hammer it in too fast.

Warranty & Support

Warranty: 12 months.

Tool Nut’s Take

Tool Nut’s Take

Simpson Strong-Tie SDS25312MB Strong-Drive SDS Heavy-Duty Connector Screw is the one you buy when you want structural bite without wasting time

This is a jobsite-friendly structural screw that cuts out extra steps, drives clean with a hex head, and makes a lot more sense than fighting with slower old-school fastening methods.

• Who it’s for: Carpenters, deck builders, remodelers, and serious DIY users installing connectors or doing exterior wood fastening.
• Why it stands out: Type-17 point, serrated threads, integrated washer, and a corrosion-resistant double-barrier coating all work together to make installation faster and more reliable.
• Worth knowing: This is a 125-pack of screws, not a kit with extra accessories, so make sure you have the right 3/8 in. hex driver on hand before you start.

Common Questions

• Does this screw require predrilling? No. The Type-17 point is designed for easy driving without predrilling.
• What drive does it use? It uses a 3/8 in. hex drive.
• What is this screw mainly used for? It is intended for heavy-duty Simpson Strong-Tie connectors and structural wood applications, including exterior wood fastening.
• What comes in this package? This SDS25312MB package contains 125 screws.