Bolt Cutting Jig




Introduction: Bolt Cutting Jig

About: I am a hard working individual. I am into electronics and mechanics mainly but can get into anything if it has to do with making our lives easier or more enjoyable.

Sometimes you get into a project and you decide you need some bolts. No big deal, its a common occurrence. You then determine the size, length, and style of bolt you wish to use. Then, if you're like me, its time to search all the places you've stored and saved bolts over the years, and with next to no luck you found the bolts that you could use, but they're too long. Bummer. Now normally, a person would probably source the right length of bolt brand new from a store or some sort of hardware supplier but sometimes, you just end up cutting them to length. It is the cold hard truth.

This is jig that I made in order to cut more than I wished to do one-at-a-time (around 50-60) in the vice like I normally would for 10 or less. It's pretty simple and works fairly good. I'll show you how I made it.

Step 1: The Jig

The jig itself isn't anything too special. Mine is actually a piece of 2"X1/4" scrap about 5" long. I found it under my welding bench. I could probably remember what it was cut off for originally but that is most likely irrelevant. The thing to take away from this step is the thickness of the jig you wish to make. The project I was working on included bolting a bunch of sheet metal panels I was bolting to a 1/8" frame work. I had a bunch of 3/4" long bolts but, what I really wanted was roughly 1/2" long bolts. The thickness of the flange nut I was using with these bolts was about 1/4".

1/4" + X = 1/2" Or...

(nut) + (spacer jig) = (desired length bolt)

Hence the 1/4" flat metal. When the bolt is tightened onto the jig, the nut is exactly where you should cut to have the same length bolts every time.

I drilled as many holes as I could fit onto the scrap piece so that I could cut batches of what was, for me, 12 bolts at a time. The spacing turned out to be 3/4" X 1" OC (on center) but that would vary on the type of bolt you wanted to cut.

Step 2: Why Make the Jig?

Well, maybe you just have a random deli tupperware full of used bolts that you saved from another project and want to re-purpose on your new project. Maybe those bolts are the wrong size. Maybe the bolts you want to use are truss head bolts like I had which, are actually, really nice to use on sheet metal. This is because of course the little serrations on the bolt head and the nut that keep them tight and the wider flange surface that spreads out the pressure on the panel without the need for a washer. Maybe you're just too cheap, like me, to buy the right ones when you need 60 ish + of them and other than the length, are a perfect fit for the project. Truss head bolts would be really hard to cut due to the rounded shaped head without bolting them through something.

A quick word about the reuse of bolts:

Please use common sense when doing this and keep in mind important factors. For example, on my project these bolts are simply attaching light sheet metal panels to a framework. There is no (real) load bearing on these bolts, rather just the weight of the panel itself. The framework does all of the weight bearing and the panels are a mere cover of sorts. In this respect, all of the corrosion, rust, previous stress applied, etc. is kind of irrelevant for this project. I just needed quantity to keep tight seams on the panels. Just things to think about. There are many different grades and styles of bolts to choose from and each one has its own intended purpose. I know I don't have to lecture but safety is very important and its always worth a mention.

Step 3: Setup and Use

Okay quick word over, onto the setup. I just put the jig in my vice and bolted bolts through all the holes. I used a 3/8" impact gun and a large flat bladed screwdriver for the installation (and removal) of the bolts from the jig. Then I just cut each one with an angle grinder fitted with a cut off wheel. When you get done you should have a pile of little cut offs.

Step 4: Clean Up

Once cut off, I dressed the cut area quickly with a 60 grit flapper wheel to get the bolt flush to the nut and to de-burr the cuts as good as possible. I then proceed to the next process which for me was a quick pass with a wire cup brush fitted into my ancient makita drill I rebuilt the battery pack in. The jig holds all the bolts nice and solid so no need for vice grips and a benchgrinder like I normally would do. This process was to remove the paint and rust.

In hindsight, with the addition of a handle on the jig, it could probably easily be used to buff the bolts on a wire wheel in a benchgrinder with no problem. However, the ancient makita method was the way I did it and it worked great for me. I did both sides even though I only have pictures of the bolt side.

Next, I can remove the nut, which, will clean whatever was left after the sanding, out of the threads. With a quick buff of the threads with a wire brush of some sort to remove rust and make sure the nut would thread on without too much fuss pretty much completes the whole process.

On to the next batch and so on. The condition of your bolts will greatly dictate how much time you would have to dedicate to the cutting process. It really did save me a bunch of time working in batches.

Step 5: Another Use!

I knew I wanted to paint these bolts straight from the get go. A great... okay way to paint bolts is to punch a bunch of holes in a grocery sack or cardboard then stick the bolts in the holes. They're highly populated for paint efficiency and the cardboard fits tight enough resulting in a bolt that is devoid of paint on the freshly cleaned threads.

Turns out the great thing about setting up your spacing for the bolts in a jig is that it is easily transferable to another medium. In the case of cardboard, I just held the jig in place and shoved a punch down through the holes to create nice evenly spaced holes to put the bolts in. Repeat multiplied by however many batches you did. I did quite a few.

After all the bolts are in the cardboard you are free to paint them whatever color you want, if at all, and they're ready for use in your project. I will most likely paint the bolts black whenever I get around to painting the frame of the project that these go to.

I hope this is useful for someone else! Thanks for checking it out!



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    5 Discussions

    I like this because it also solves the thread cleaning problem! often when you cut a bolt off, the end threads get messed up. best way to fix this i've found is to thread a nut on to the bolt before cutting, then cut, then take the nut off. backing the nut back off cleans up the threads a bit. since you hold yours on to your jig with nuts, it's a very elegant solution.

    for bolts that need to have a high degree of accuracy, or have fine threads, i recommend doing the above, but with a die instead of a nut. the die will straighten the threads like a nut would, and cut the ones it can't. keeps you from possibly losing a bolt and nut if the threads get messed up worse than a nut can straighten.

    Nicely done! I usually have to cut just one or two at 3 am the night before I need the project hardware store open! Time to improvise. It will be nice to use this technique to be prepared for that eventuality.

    1 reply

    I mostly end up cutting one to ten bolts to length at a given time...oddly enough, its usually in the a.m. as well. Sometimes you gotta do more though and that's when little tips and tricks help you out. Its always the little things. Thanks for checking it out!

    More important than the jig, how tasty was the Ultra Thin Honey Ham? ☺

    Really though, nice jig for doing multiples.

    1 reply

    There is no amount of "haha" that can describe to the extent that I was laughing when I initially read your comment. I posted this at like 3 am and then woke up several hours later to head to work. Sleep deprivation laugh. Classic. Thank you sir, and thank you for checking my Instructable out!