How do I optimally cut a bolt to length?

Question

Once in a while I need a bolt of exactly the right length and it is not one of the lengths available in stores. So I get a longer bolt and cut it to length. Here's the procedure I follow.

I screw one or several nuts onto the bolt so that they are between the bolt head and the future cut. Then I grip the bolt in a vise and cut it with a hacksaw. Then I trim the edges with a file to get them to something like 45 degrees. Finally I ungrip the bolt and unscrew the nuts and that cleans the threading of any loose metal.

What I don't like is trimming the edges requires a lot of tedious work and usually the edges won't be as clean as they were on the original bolt and so the bolt will sometimes get stuck when I start to screw a nut onto it and I'll have to remove the nut and try to screw it again. This it not a problem when the connection is to be permanent, but is definitely a problem when it has to be disconnected and connected back rather often.

Also it's quite problematic to have a cut perfectly orthogonal to the bolt axis because the threading helps the saw blade to slightly drive away. This is not a major problem, but still would be better to avoid.

Is there a more efficient procedure for cutting bolts to length that would yield cleaner edges and more precise cuts?

Answer 1

After cutting the bolt to length, use a stationary grinder instead of a file to clean up your work. With a grinder, it's easy to square up the end of the bolt and apply the chamfer that you want.

Just be careful, especially if the bolt is shorter than the grinder's table. If the bolt is short, use a pair of vice grips to hold the bolt during grinding. And remember that the end of the bolt is going to be very hot after grinding!

Answer 2

You are doing it the optimal way for somebody that just does it occaisonally. A cut that is more square across the bolt (OK - orthogonal...) can be had by using a motorized chop saw with an abrasive blade, an a grinder will help the clean-up, like Caleb says.

If you were to do it this way, you don't need the nut threaded on to clean out the threads. BUT... it kinda sounds like you have a non-problem here. Every blue moon you have to cut a bolt and it takes a little extra time to get the nut on? That doesn't sound so bad.

Answer 3

You could try putting a nut on either side of the cutting blade to square the cut and to stop the blade from drifting along the thread.