Getting the Right Lag Screw Sizes For Your Fastening Needs

Getting the ideal Lag screw sizes for your fastening needs helps you install your materials safely and efficiently. Hex lag screws (also known as lag bolts) feature spaced threads that distribute clamping force over a wide area, helping to reduce stress on your materials and minimize damage during installation. They also have sharp points and are available in various sizes to suit different applications. Before you can install your hex lag screws, ensure that all the materials are aligned and secure using clamps. Then, use a drill bit that is slightly smaller than the screw’s body diameter to create a pilot hole.

Unlike standard wood screws, which have coarse threading that extends the length of the screw, lag screws have a shallower, sharper, and more specific lag thread that is designed to install in wood without a nut. They can also be used with lag shields to protect the heads from excessive wear and tear during installation.

Hex lag screws come in either square or hex head styles and can be purchased with reduced or full body diameters. A hex head will provide more torque capacity and has the added benefit of being easier to grip with a wrench.

Unless otherwise specified, the hex lag screws manufactured by Portland Bolt will possess a semi-cone point instead of the gimlet point usually supplied on imported hex lag bolts. A stepped pilot hole should be drilled prior to installing large diameter lag screws to ensure the heads do not break under too much torque. See the chart below for recommended pilot hole dimensions based on bolt size and wood species. Lag screw sizes