Installing carriage bolts in wood is a straightforward process that involves inserting the bolt, ensuring its square shoulder sits flush, and securing it with a washer and nut. Here's a step-by-step guide:
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Drill the Hole: The diameter of the hole needs to be slightly larger than the diameter of the carriage bolt shaft. Ensure the hole is perpendicular to the wood surface for proper alignment.
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Insert the Carriage Bolt: Insert the carriage bolt through the hole, with the rounded head facing outwards (away from the wood you'll be tightening against).
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Seat the Shoulder: As you push the bolt through, the square shoulder (the section directly beneath the head) should press firmly and snugly into the wood. The purpose of the square shoulder is to grip the wood and prevent the bolt from turning when the nut is tightened. In softer woods, you might need to lightly tap the bolt head to fully seat the square shoulder.
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Add a Washer: Place a washer over the threaded end of the carriage bolt. The washer helps distribute the pressure from the nut, preventing it from digging into the wood and providing a more secure hold. Using a fender washer (a washer with a larger surface area) is often recommended, especially with softer woods, for even greater load distribution.
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Attach and Tighten the Nut: Screw the nut onto the threaded end of the carriage bolt. Tighten the nut with a wrench. The square shoulder of the carriage bolt should prevent it from turning as you tighten the nut. If the bolt does turn (especially in softer woods), you might need to hold the bolt head with pliers or another wrench while tightening the nut.
Summary:
To install a carriage bolt in wood, drill the correct size hole, insert the bolt (rounded head out), seat the square shoulder, add a washer, and tighten the nut. This creates a strong and secure fastening.
