The length of a lag screw is measured from the under head bearing surface to the tip of the screw
Hex head is easily driven with simple wrenches and requires minimal clearance above the fastener
Hex Lag Screws are used for directly fastening into wood surfaces. They are used with a lag shield and lag screws can be used in masonry applications. The hex head is six-sided and ideal for easy driving and quick installation. The threads on lag screws are designed to embed into the wood, rather than relying on a nut to secure the connection.