How to Install and Remove a Carriage Bolt

Carriage Bolt Install and Removal

The Setup

The first thing we need to do when installing a carriage bolt is to make sure we have the right parts and tools to do so. For this job we will need a:

For our example, we have already pre-drilled the hole into a piece of 2×4 and attached it to a vice. This will act as our installation surface for our carriage bolt.

Understanding A Carriage Bolt

carriage bolt setup

A carriage bolt is a bolt with threading all the way up the shank to a small square shoulder, with a domed head. The square shoulder of a carriage bolt stops it from spinning as it is screwed into the surface of a material. You would not typically use this type of bolt on very hard wood as it may not properly dig into the material, which would cause the bolt to spin in place. Once you seat the bolt through the hole, it is the job of the nut and washer to pull the bolt into the material tightly. Since there is no drive device for the domed head of the bolt, this is the only way to install it.

The Install

The installation process is fairly simple. First, you drill a hole into the wood for the appropriate size (diameter) of the bolt. Next you slide the bolt into the hole (you may need a hammer as the hole should be just big enough for the bolt to go through).

drill the hole

Now that you have the nut through the wood it is time to attach the nut and  the washer. Place the washer on the rear side of the bolt followed by the nut. The washer will help to distribute the force you are about to put onto the nut to pull the bolt into the wood. This will not only protect the wood on the back side but also keep the bolt from digging into it and getting stuck.

tighten nut with washer

As you tighten the nut, the square shoulder on the bolt will be pulled into the wood. Once the underside of the head rests against the wood, the carriage bolt is officially installed.

The Removal

Removing the carriage bolt is a fairly simple process. First, you will want to twist the nut close to the end of the bolt. DO NOT TAKE THE NUT ALL THE WAY OFF THE BOLT, you will need it to help move the bolt along.

prepare to remove and loose nut

Once the nut is backed off to the end of the bolt, hit the nut with a hammer. The force  should start moving the square shoulder out of the wood. As you move the  bolt further out the nut will get closer to the wood. When this happens continue to back out the nut and strike it again. Repeat this process until the bolt is loose enough to take out by hand or the nut can no longer grip the bolt.

push out bolt with hammer

If you find the bolt is stuck but the nut can no longer attach to the bolt, use the nail remover attached to the hammer and use it to pry the bolt out of the hole.

removing process is complete

It’s That Simple

There you go now you know everything you’ll need to know about installing and  removing carriage bolts. As always, Albany County Fasteners stresses the need for protective gear while working with dangerous materials. Remember to ALWAYS wear safety glasses while drilling to protect your eyes and wear protective gloves that fit to keep your hands safe from harm as well.

Full Installation and Removal process you can find on our Youtube channel

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