How to tighten a carriage bolt

bolts

I'm trying to assemble a glider patio chair which I ordered. The main pieces (seat, back, sides, etc) are assembled and I'm supposed to just screw the pieces together. How are you supposed to tighten these things? There's nowhere to use a screwdriver to hold it in place when tightening the nuts. The holes aren't big enough for the bolts to go in flush, and they're tight enough that I'm having to screw the bolts to get them to go all the way in. Last time I used carriage bolts on something I built myself, I think the holes were loose enough that I could just push the bolts through and then tighten them with nuts. I don't remember how I held the bolts in place while tightening them on that last project.

Am I supposed to re-drill the holes bigger so I can just slip the bolts in flush?

There is is a good picture of a carriage bolt here.

Best Answer

Do not drill the holes bigger in the wood parts. The idea with carriage bolts is that you pound them in with a hammer so that the square part under the head of the bolt is forced down into the tight hole in the wood. This provides the hold to a) keep the bolt in place during assembly and b) to keep the bolt from turning while using a wrench or socket to tighten the nut from the end of the bolt.

Carriage bolts are designed so that on one side of an assembly that there are no protruding bits for things to catch on. The rounded head will provide that as opposed to there being a hex or square head sticking out. In your case with a chair kit the general idea is that the heads of the carriage bolts should face toward the side of the chair where the user will be. As such the threaded bolt ends will want to be down underneath or toward a generally non used surface of the chair.