Lag bolts, also referred to as lag screws, have a pointed end and are the most suitable fasteners for joining wood with other material.

Depending on your requirement for bolt strength and the corrosiveness of the operating environment, you can select lag bolts of different types such as zinc plated, hot dipped galvanized, silicon bronze or stainless steel.

Zinc plated lag bolts are suitable for indoor applications, as they provide moderate protection against rust. Hot dipped galvanized bolts are suitable for applications in coastal areas, as they have good corrosion resistant properties. You can use silicon bronze lag bolts for constructing and repairing wooden boats, as bronze has more pre-load strength and higher corrosion resistance. Stainless steel lag bolts are the strongest and have the highest corrosion resistance among all lag bolts. However, steel lag bolts are also the most expensive lag bolts.

Some of the important parameters you must consider before purchasing a lag bolt are:

1. Required strength of the lag bolt
2. Corrosion resistance of the lag bolt
3. Required quantity

Action Steps
The best contacts and resources to help you get it done

Buy lag bolts from reputable manufacturers

Once you understand the requirement and the type of lag bolts you need, check out lag bolts available with reputable manufacturers.

I recommend: Associated Fastening, a supplier of a variety of fasteners for OEM (original equipment manufacturer), provides square and hex lag screws. You can buy a galvanized lag screw or a zinc-plated lag screw at Hodell-Natco Industries. Sanson & Rowland, a reputable fastener manufacturer, offers inch and metric lag screws. Pacific Marine & Industrial is a manufacturer of marine products that also supplies ring lag bolts. Suncore Stainless manufactures lag ringbolts and eye lag screws.

Buy lag bolts from distributors

You can also buy lag bolts from online distributors. You can ask for a discount for bulk orders.

I recommend: Hudson Fasteners, a distributor of industrial fasteners, offers tamper-proof lag bolts. Ziegler’s Bolt and Nut supplies hex black oxide bolts and hex zinc bolts. Albany Steel & Brass is another distributor of lag screws, including tamper proof lag screws. You can buy concrete lag bolts from Fastenal.

Order specialty lag bolts

For non-standard requirements, you can order specialty lag bolts such as large diameter lag bolts or extra long lag bolts.

I recommend: Coltwell Industries, a manufacturer of standard bolts, offers corrosion resistant, extra long lag bolts. You can also order large lag bolts at Archer Engineering, another supplier of metric bolts and screws. EPS manufactures cold-headed fasteners, including lag bolts. Chicago Nut & Bolt is another manufacturer that supplies customized steel lag bolts.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Ensure that your lag bolt supplier follows the standards adapted by your design engineers.
• •  Use heat-treated lag bolts for special application requirements, such as high load carrying capacity and shear strengths.