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. The neck of the carriage bolt fits snugly into a square hole in the wood to prevent it from rotating while the nut is tightened. Lag bolts, in contrast, do not have a neck and can be directly driven into the wood without drilling a pilot hole.
Carriage bolts are commonly used for applications where a smooth surface is important, while lag bolts are better suited for applications where strength and holding power are critical. Carriage bolts are perfect for attaching items that require a snug fit and won’t rotate, such as a wooden handrail or a bench. This is because the smooth and round head won’t protrude from the surface of the wood, making it an excellent choice for projects where aesthetics matter.
If you need to attach heavy objects to wood, such as a treehouse or a swing set, lag bolts are the way to go. This is because they have thicker and coarser threads, providing better 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.
Choosing between carriage bolts and lag bolts requires careful consideration of various factors. The first factor to consider is the type of wood being used. Hardwoods, for instance, need longer and thicker bolts to ensure adequate holding power. The weight of the object being fastened to the wood is another important consideration. Heavy objects require a stronger and more secure fastening method, such as lag bolts. Lastly, the intended use of the project should also be taken into account.
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 a variation of lag bolts that are frequently used. Square head lags have a square head, which provides a better grip when using a wrench compared to their hexagonal counterparts. Square head lags are typically used for heavier-duty applications where more holding power is required.
Ultimately, the selection between carriage bolts and lag bolts relies on the particular requirements of your undertaking. 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.