How to Install a Lag Bolt
For sheer holding power and ease of installation, it's tough to beat lag bolts. Sometimes referred to as lag screws, these fasteners are used to join pieces of wood. They may be made of bright, galvanized or stainless steel, brass, or silicon bronze. They are available in a wide variety of lengths and diameters. Essentially the bigger the pieces of wood to be joined, the bigger the lag bolt you should use. But regardless of their dimensions, all lag bolts are "screwed in" with some type of wrench. For this example, we'll assume you are joining two framing members together. Does this Spark an idea?
Other People Are Reading
Things You'll Need
- C-clamp(s)
- Level
- Drill/drill driver
- Drill bit
- Metal washer
- Lag bolt of appropriate diameter and length
- Wrench (socket, box, adjustable or hammer)
- Breaker bar (optional)
Instructions
-
Installation
-
1
Clamp the two framing members together tightly using the c-clamps. If needed, use your level to ensure they are true.
-
2
Bore a pilot hole roughly three-quarters the size of the lag bolt's shank diameter and about two-thirds as deep as its length with the drill. If you drill too small or shallow a pilot hole, the driving stress may snap the bolt shank. Too large or deep, and the bolt will not dig in enough to provide sufficient holding power.
-
-
3
Slip the washer onto the lag bolt and insert the bolt into the pilot hole.
-
4
Drive the lag bolt home until the washer just begins to bite into the surface of the wood using the wrench type of your choice and turning it in a clockwise motion.
-
5
If the framing members require additional bolts to be installed, repeat Steps 2 - 4.
-
1
Tips & Warnings
If you are driving a larger diameter lag bolt, you may want to slip a breaker bar over the end of your wrench. Using it will provide you with additional leverage and torque. Galvanized and stainless lag bolts are often used where moisture is present because of their resistance to rust and corrosion. Lag bolts are available at most hardware and home improvement stores.
