The Simpson #7 2-1/4 in. Self-Drilling Siding Screw in Type 410 Stainless Steel is purpose-built for attaching wood siding, wood panels, and metal trim directly to steel studs and steel framing without pre-drilling. The trim head profile, #3 drill point, and #1 square drive work together to deliver clean, efficient fastening in light-gauge steel construction and exterior cladding applications.

Key Features

• Trim Head Design - The low-profile head sits flush and unobtrusive against siding and panel surfaces, producing a clean finished appearance with minimal surface disruption.
• #3 Drill Point - The self-drilling tip bores directly through steel framing without a pilot hole, saving time and reducing steps during installation.
• #1 Square Drive - Provides positive bit engagement and reduces cam-out during driving, giving installers better control and consistent torque transfer on the job.
• Type 410 Stainless Steel Construction - The hardenable stainless alloy gives the screw the strength needed to penetrate metal substrates while standing up to the demands of exterior siding and framing environments.
• 2/3-Shank Thread Length at 19 TPI - The extended threading pattern bites aggressively into substrates, promoting secure pull-through resistance in wood-to-steel fastening applications.

Why This Product

• Eliminates Pre-Drilling - The #3 drill point drives directly into steel studs, cutting out a preparation step and keeping siding and trim installation moving efficiently on steel-framed structures.
• Engineered for Wood-to-Steel Fastening - Simpson designed this screw specifically for attaching wood siding, wood panels, and metal trim to steel framing, so it matches the mechanical demands of those connections by design rather than by approximation.
• Clean Appearance on Finished Surfaces - The trim head keeps fastener visibility low on exposed siding and panel faces, which matters on any project where the final look is part of the deliverable.
• Hardened Stainless for Dual-Duty Performance - Type 410 Stainless Steel combines the hardenability required to self-drill through metal with stainless construction, making it a practical fit for exterior steel-stud applications where a standard carbon steel screw would not be appropriate.

Specifications

• Model Number: F07T225TDM
• Screw Size: #7
• Length: 2-1/4 in.
• Head Diameter: 0.230 in.
• Head Type: Trim Head
• Drive Type: #1 Square
• Point Type: #3 Drill Point
• Thread Length: 2/3 of shank
• TPI: 19
• Material / Coating: Type 410 Stainless Steel
• Packaging Quantity: 1,000 pieces

Approved Applications

• Attaching wood siding to steel studs
• Fastening wood panels to steel framing
• Securing metal trim to steel studs

What's Included

• 1,000 x Simpson #7 2-1/4" Self-Drilling Siding Screws (Type 410 Stainless Steel)

Frequently Asked Questions

What material are these screws made from?

These screws are manufactured from Type 410 Stainless Steel, which can be hardened through heat treatment, giving it the ability to drill through metal substrates.

Does Type 410 Stainless Steel offer the same corrosion resistance as Type 316 or Type 305?

No. Type 410 Stainless Steel does not offer the same level of corrosion resistance as either Type 316 or Type 305 stainless steel. Its primary advantage is its hardenability for metal-drilling applications.

What replacement bit is compatible with this screw's drive type?

This screw uses a #1 Square drive. The compatible replacement bit model is BIT1S-2-R2.

Do product dimensions or thread length always match product images?

Product dimensions and/or thread length may differ from the picture. Always refer to the written item description and specifications for accurate measurements.

Note: Product dimensions and/or thread length may differ from picture. Please see item description for specifications.