#17 x 4″ CTX T-40 Bronze Construction Lag Screws

The Ultimate Lag Screw for Superior Strength and Durability

Big Timber’s CTX™ Construction Lag Screws are the ultimate choice for rugged, structural applications that demand reliability. Heat-treated and hardened for top-tier performance, these screws are engineered to be stronger and more durable than standard lag screws, providing exceptional holding power in even the toughest environments. With a corrosion-resistant triple coating, deep-cutting threads, and a built-in washer head for a clean, professional finish, these screws go beyond the basics to ensure every project stands strong.

Key Features That Set CTX™ Lag Screws Apart

• Triple-Layer ACQ-Compatible Coating
  Designed to withstand the elements, these lag screws feature a triple-layer bronze coating rated for 1200 hours of corrosion resistance in ACQ and salt spray conditions, making them ideal for both indoor and outdoor applications.
• Enhanced Holding Power
  Built with aggressive threads, deep six-lobe star drive, and a round washer head, these screws deliver unmatched grip and pull-through strength, keeping your build solid and secure. The Type 17 point ensures fast, precise starts without “walking” or the need for pre-drilling.
• Smooth Installation Every Time
  Each screw features under-head cutting nibs for self-countersinking, while the wax coating reduces torque for an easy, fast drive. V-cut notches on the threads reduce splitting and minimize drag, helping to draw lumber together seamlessly.

Tough Enough for Any Structural Project
Ideal for log construction, timber frames, laminated beams, girders, ledger boards, stair rails, deck posts, fencing, SIP panels, and pole barns, these lag screws are backed by certified independent testing (TER 1907-01) and meet International Building Code and Residential Code standards.

Specifications & Options

• Available Quantities: 1 piece, 25 pieces, 100 pieces, and bulk cartons
• Product Dimensions: Diameter options to handle high shear and tensile loads, ranging from 1” to 16” lengths
• Average Ultimate Load: 1,850 lbf (shear strength: 1,240 lbf) for 4” T-40 screws, ensuring stability in the most demanding conditions

For environments with high corrosion risk—such as areas near saltwater, pools, or livestock confinement—choose Big Timber’s SCTX stainless steel fasteners for maximum durability.

Proven Tough and Tested
These lag screws are engineered and certified to be the superior alternative to galvanized screws, with durability and holding power that mountain-tested builders rely on.

Dimensions

Specifications