Simpson #8 x 1-1/4" Self-Drilling Wire-Lath Modified Truss-Head Screw in Type 410 Stainless Steel is a professional-grade metal fastener engineered for securing metal lath to steel studs and attaching corrugated siding panels to steel framing - no predrilling required. Designed by Simpson Strong-Tie, this self-drilling screw delivers reliable holding power in residential, agricultural, and commercial construction applications where a low-profile head and corrosion-resistant metal are essential.

Key Features

• Type 410 Stainless Steel construction - can be hardened through heat treatment, giving the screw the ability to drill through metal without a separate pilot hole, saving time and labor on the job site.
• Modified Truss Head with 0.42 in. head diameter - wide, low-profile bearing surface distributes clamping load evenly across wire lath and corrugated panels, reducing the risk of pull-through.
• #2 Phillips drive - compatible with standard drill drivers and screwguns, allowing fast, controlled installation without requiring specialty tools.
• Self-drilling drill point - penetrates steel studs and metal substrates quickly without "walking," making it ideal for lath and siding panel applications where speed and accuracy matter.
• 18 TPI tapping threads - coarse thread pitch bites aggressively into metal, creating a strong mechanical connection that resists pull-out in structural and cladding applications.
• Max grip length of 0.791 in. - accommodates stacked material thicknesses, supporting reliable fastening across varying panel or lath configurations.
• 1-1/4 in. overall length - sized precisely for thin-metal-to-steel-stud connections, minimizing over-penetration while ensuring full thread engagement.

Why This Product

• Eliminates predrilling on metal substrates - the drill point design penetrates steel studs in a single step, reducing installation time and the need for extra tools on wire lath and corrugated siding projects.
• Purpose-built for wire lath and corrugated siding applications - the modified truss head profile and tapping thread configuration are specifically matched to the demands of metal lath-to-stud and panel-to-stud connections, unlike general-purpose screws.
• Stainless steel durability in metal construction environments - Type 410 stainless resists corrosion in typical construction conditions and, unlike carbon steel fasteners, will not rust-stain surrounding materials in these applications.
• Trusted Simpson Strong-Tie engineering - designed to meet the strength and performance requirements of residential, agricultural, and commercial metal framing projects, providing confidence in long-term fastener integrity.

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #8
• Length: 1-1/4 in.
• Head Type: Modified Truss Head
• Head Diameter: 0.42 in.
• Drive Type: #2 Phillips
• Thread Type: Tapping Threads
• TPI: 18
• Point Type: Drill Point
• Max. Grip Length: 0.791 in.
• Material: Type 410 Stainless Steel
• Country of Origin: Taiwan

Available Pack Options

• F08T125KDC: 100 Pk
• F08T125KDM: 1000 Pk
• F08T125KDB: 4000 Pk

Approved Applications

• Fastening metal wire lath to steel studs
• Attaching corrugated siding panels to steel studs

Frequently Asked Questions

Does this screw require predrilling before installation into steel studs?

No. This fastener features a drill point that self-drills into steel studs and metal substrates without the need for a pilot hole, allowing for fast, single-step installation in wire lath and corrugated siding applications.

What is the difference between Type 410 stainless steel and other stainless grades like 316 or 305?

Type 410 stainless steel can be hardened through heat treatment, which gives it the hardness needed to drill through metal. However, it does not offer the same level of corrosion resistance as Type 316 or Type 305 stainless steel. It is well suited for metal framing and lath applications in typical construction environments.

What drive tool is needed to install this screw?

This screw uses a #2 Phillips drive, which is compatible with standard drill drivers and screwguns - no specialty bits are required.

What head type does this screw use, and why does it matter for lath applications?

This screw features a Modified Truss Head with a 0.42 in. head diameter. The wide, low-profile design spreads the clamping force across a larger surface area, which helps prevent the fastener from pulling through wire lath or thin corrugated metal panels during and after installation.

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