Carriage Bolts vs. Lag Bolts: Which to Choose?
Securing wood can be done through different methods, and two commonly used options are carriage bolts and lag bolts. Carriage bolts feature a round, smooth head with a square or hexagonal neck, while lag bolts have a hexagonal head with a coarse thread. Carriage bolts’ neck is designed to fit into a square hole in the wood to prevent it from rotating when the nut is tightened. Lag bolts lack a neck and can be inserted directly into the wood without the need for a pilot hole.
The best choice between carriage bolts and lag bolts depends on the application, with carriage bolts typically preferred for aesthetics and lag bolts for strength and durability. If you need to attach something that requires a secure and non-rotating fit, like a wooden handrail or a bench, carriage bolts are an excellent option. The round and smooth head of a carriage bolt won’t protrude from the wood’s surface, making it ideal for projects where looks are important.
If you need to attach heavy objects to wood, such as a treehouse or a swing set, lag bolts are the way to go. Lag bolts have a coarser thread than carriage bolts, which gives them a stronger grip and holding power in wood. Additionally, lag bolts are less likely to loosen over time, making them a reliable option for long-term use.
Several factors should be taken into account when deciding between carriage bolts and lag bolts. One factor to consider is the type of wood being fastened together. Hardwoods, for example, require longer and thicker bolts to provide adequate holding power. The second factor to consider is the weight of the object being attached to the wood. For heavy objects, a more secure fastening method like lag bolts is necessary. The project’s intended use should also be considered.
Selecting the right size bolt is crucial for the success of the project. Using a bolt that is too small or too short will not provide sufficient holding power, while using a bolt that is too long may damage the wood. Consulting a professional or a hardware store is recommended to determine the correct bolt size for your project.
Square head lags are another type of lag bolt that is commonly used. Square head lags have a square head instead of a hexagonal head, which provides a better grip when using a wrench. They are usually employed in heavy-duty applications that require greater holding power.
To summarize, the decision between using carriage bolts or lag bolts comes down to the specific demands of your task. Carriage bolts are ideal for use in wood-to-wood connections, as they provide a smooth finish and are less likely to damage the wood. However, if you need to tackle heavy-duty projects, like anchoring large beams and frames to wooden posts or concrete, lag bolts are the way to go.