The Simpson Strong-Drive SDS Heavy-Duty Connector Screw in 1/4 in. diameter by 3-1/2 in. length is a high-strength structural fastener engineered for demanding connector installations, wood-to-wood assemblies, and engineered wood applications. Fabricated from Type 316 stainless steel, this screw delivers maximum corrosion resistance in higher-exposure environments such as coastal, marine, and chemically aggressive settings - making it a reliable choice wherever standard carbon-steel fasteners would be at risk. With no predrilling required, it streamlines installation and reduces labor time on structural connector work.

Key Features

• Type 316 Stainless Steel construction - provides superior corrosion resistance in harsh, high-moisture, and salt-air environments where standard coated screws are inadequate, ensuring long-term structural integrity
• Type-17 point - enables fast, no-predrill installation by cutting through wood fiber cleanly, reducing split risk and saving time on every fastening task
• Serrated threads with 10 TPI - bite aggressively into wood and engineered lumber for a secure, vibration-resistant hold that maintains clamping force over time
• 3/8 in. hex head with 0.235 in. shank diameter - compatible with standard hex drivers for quick tool engagement and consistent torque delivery during installation
• 2-1/4 in. thread length - provides substantial thread engagement into the base material, maximizing withdrawal resistance in structural connector applications
• Extensively tested design - has been verified across a wide range of connector and structural wood applications, giving installers confidence in code-compliance and load performance

Why This Product

• Matched to Simpson Strong-Tie stainless steel connectors - designed specifically to fasten Simpson Strong-Tie stainless steel hardware, ensuring galvanic compatibility and eliminating the accelerated corrosion that can occur when mismatched metals are used together in high-exposure conditions
• No predrilling required - the Type-17 point allows direct installation into wood and engineered wood without pre-boring, cutting steps from the job and reducing the chance of misalignment between pilot hole and connector hole patterns
• Built for high-exposure environments - Type 316 stainless steel is appropriate where maximum corrosion resistance is required, such as coastal construction, pressure-treated lumber contact, and applications exposed to chemicals or persistent moisture
• Same proven installation feel as standard SDS screws - offers the same easy-driving, split-reducing performance as the standard SDS line, so crews already familiar with SDS fastening require no adjustment in technique or tooling

Specifications

• Brand: Simpson Strong-Tie
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Length: 3-1/2 in.
• Shank Diameter: 0.235 in.
• Drive Type: 3/8 in. Hex
• Head Type: Hex Head
• Thread Type: Serrated Threads
• Thread Length: 2-1/4 in.
• TPI: 10
• Point Type: Type-17 Point
• Country of Origin: Taiwan

Available Pack Options

• SDS25312SS-RP5: 5 Pk
• SDS25312SS-R25: 25 Pk
• SDS25312SS-R25L: 25 Pk (L) - includes (1) 3/8-in. hex-driver bit
• SDS25312SS: 900 Pk

Approved Applications

• Fastening Simpson Strong-Tie Connectors

Install With

• A low-speed 1/2-in. drill with a 3/8-in. hex driver is the recommended tool for installation

Frequently Asked Questions

Why use Type 316 stainless steel screws instead of standard coated SDS screws?

Type 316 stainless steel screws are intended for higher-exposure environments where maximum corrosion resistance is required - such as coastal or marine settings, applications with persistent moisture exposure, or where chemical contact is a concern. Standard coated screws may not provide sufficient protection in these conditions, whereas Type 316 stainless steel maintains structural performance long-term.

Do these screws require predrilling before installation?

No predrilling is required. The Type-17 point is specifically designed to drive directly into wood and engineered wood substrates without a pilot hole, reducing installation time and the risk of misalignment when fastening connectors.

What tool is recommended for installing these screws?

A low-speed 1/2-in. drill with a 3/8-in. hex driver is the recommended installation tool. The 3/8-in. hex head on the screw is sized to engage this driver directly for consistent torque and controlled installation.

Are these screws compatible with engineered wood products as well as dimensional lumber?

Yes. The Strong-Drive SDS Heavy-Duty Connector Screw is designed for both wood-to-wood and engineered wood applications, in addition to connector installations. The serrated thread design and Type-17 point work together to drive securely into a range of structural wood materials without splitting.

Note: The image displayed is a generic representation of the type of product. Product dimensions and/or thread length may differ from picture. Please see the item description above for specifications.