15 x 4 in. Big T Wafer Head Black Lag Screws, Qty:400

15 x 4-in. Wafer-Head WTX Lag Screws, Star-Drive, Black - Qty: 400

Built for demanding structural and outdoor fastening applications, these 15 x 4-in. Wafer-Head WTX Lag Screws combine heat-treated steel construction, an aggressive thread design, and a durable black corrosion-resistant coating. Designed for professionals and serious DIYers, they are well suited for log construction, timber framing, decking, landscaping, and other heavy-duty wood fastening projects.

Professional-Grade Structural Fasteners

Big Timber WTX Lag Screws are engineered to provide strong holding power and reliable installation in a variety of wood applications. The wafer-style head incorporates a built-in flat washer surface that installs flush against the material, helping distribute clamping force and increase resistance to pull-through. The deep six-lobe Star Drive recess provides secure bit engagement and helps reduce cam-out during installation.

Benefits and Features

• Heat-Treated Steel Construction: Provides high strength for demanding fastening applications.
• Durable Black Coating: Provides corrosion resistance for exterior and interior applications.
• Compatible with Treated Lumber: Designed for use with treated lumber when installed according to applicable recommendations.
• Wafer-Head Design: Built-in flat washer head installs flat against the material for increased pull-through strength.
• Deep Six-Lobe Star Drive: Provides positive bit engagement and helps reduce cam-out during installation.
• Aggressive Thread: Delivers strong withdrawal resistance and dependable holding power.
• Easy Installation: Pre-drilling is not required in most materials, helping speed up installation.
• Structural Lag Screw: Backed by certified independent testing under TER 1907-01.
• Code Compliant: Meets applicable International Building Code and International Residential Code requirements.
• Large Quantity: Includes 400 screws, making this package well suited for larger construction and woodworking projects.

Common Applications

• Log Construction
• Timber Frames
• Laminated Beams
• Girders
• Ledger Boards
• Stair Rails
• Deck Posts
• Fencing
• SIP Panels
• Pole Barns
• Landscaping and Outdoor Structures
• Heavy-Duty Wood-to-Wood Connections

Designed for Demanding Wood Projects

The 15 x 4-in. WTX Lag Screw provides the length and structural fastening performance needed for substantial wood-to-wood connections. Its combination of heat-treated steel, corrosion-resistant black coating, aggressive threads, and Star Drive head makes it a practical choice for construction professionals, contractors, woodworkers, and experienced DIYers.

Quantity: 400 screws

Size: 15 x 4 inches

Drive: Six-lobe Star Drive

Head Style: Wafer head with built-in flat washer

Finish: Black corrosion-resistant coating

Note: Always follow the lumber manufacturer's recommendations and applicable building codes when selecting and installing structural fasteners.