ThruLOK is a multi-purpose wood-to-wood structural fastener that replaces carriage or through bolts. It is perfect for specific applications such as multiple beams, trusses, deck posts and many places where a traditional carriage or through bolt is used. ThruLOK performance and corrosion resistance are guaranteed for the life of the project when used in accordance with the installation instructions and supporting technical literature included in all packaging. ThruLOK is tested and backed by engineering data that conforms to the most current ICC standards. It is also approved for use on ACQ or treated wood. The ThruLOK system combines the strength of a through bolted connection with the speed of a LOK fastener without the need for pre-drilling. It can be used for applications including multi-layer beams, deck posts, carrier beams and more. Brand Name: FastenMaster Sub Brand: ThruLOK Size: 1/2 in. Length: 6-1/4 in. Head Type: Hex Finish: Galvanized Material: Steel Product Type: Lag Screw Number in Package: 1 Pack Packaging Type: Box Thread Type: Coarse Minimum Thickness: 4-1/2 inches. ACQ Approved: Yes Maximum thickness: 5-1/4 inches.