#17 x 10″ T-40 Construction Lag Screws

The Heavy-Duty Lag Screw Built to Outperform

Big Timber’s CTX™ Construction Lag Screws are crafted for demanding structural applications where reliability is key. With a 10-inch length and triple-coated bronze finish, these screws are heat-treated and hardened to deliver superior tensile and shear strength, making them the preferred alternative to standard lag screws. Built for both interior and exterior use, they resist corrosion in tough environments, providing 1200 hours of protection against ACQ and salt spray.

Exceptional Features of Big Timber CTX™ Lag Screws

• Triple-Layer Corrosion Resistance
  Designed with a triple-layer bronze coating, these screws are ACQ-compatible and provide exceptional abrasion and corrosion resistance, ideal for long-lasting, weatherproof applications.
• Precision Star Drive & Washer Head
  The six-lobe star drive reduces cam-out, doubling the torque-handling capacity of Phillips or square drives and extending the life of the bit. The integrated washer head increases pull-through strength, providing a clean, professional look with smooth edges.
• Aggressive Knurl and Type 17 Tip
  These screws feature an aggressive knurl that enlarges the hole to reduce splitting, while the Type 17 tip offers quick, precise starts with minimal “walking”—no pre-drilling required. The under-head cutting nibs also allow for self-countersinking, creating a secure, flush finish.

Applications for Any Tough Structural Project
Ideal for log construction, timber frames, laminated beams, girders, ledger boards, stair rails, deck posts, fencing, SIP panels, and pole barns, these structural lag screws are mountain-tested and crafted to meet the highest standards. Independently tested and compliant with the International Building Code and Residential Code, they are backed by certified performance (TER 1907-01).

Specifications & Options

• Available Quantities: 1 piece, 100 pieces, or 250 pieces
• Product Weight: Individual screws weigh .116lb, with packages available in 11lb and 30.1lb
• Load Capacity: Handles an average ultimate load of 1,850 lbf and a shear strength of 1,240 lbf for 10” T-40 screws.

Big Timber Warranty
Big Timber guarantees these screws to be free from material and manufacturing defects. If a product is deemed defective, it will be replaced at no cost. Please note, the warranty does not cover labor or installation-related costs.

Note: For projects within a mile of saltwater, near swimming pools, or in other high-corrosion areas, consider Big Timber’s SCTX stainless steel fasteners for optimal durability.

Built for builders who need strength and reliability in every detail, Big Timber CTX™ lag screws are ready to meet any challenge.

CTX Standard Lag Screw Dimensions

Specifications