Proper bolt cutting procedure

[Double_Down]

What is the proper procedure for cutting down the threaded portion of a bolt, yet still having the threads usable? I'm guessing taking a cutoff wheel to the bolt isn't it. :p

In order to get the proper length shank portion, I had to get a much longer bolt than required. This is for a 9/16" fine thread bolt, if that matters.

Thanks.

[NoBrakes Drake]

I don't know if it's proper, but I've run a nut past the cut off point in the past and used a hacksaw when no other tools or dies were available. Worked for me.

Good luck.

[dezertdude]

cut it with a cut off wheel or sawzall then round off the very end of the threads gently on a belt sander or chop saw. remove any burrs stuck inside the threads, and test with a nut. best (only) method Ive come up with.

[D-rek]

I don't know if it's proper, but I've run a nut past the cut off point in the past and used a hacksaw when no other tools or dies were available. Worked for me.

Good luck.

Agreed then clean off the threads on a grinder or sander.

[DSRacing]

I've always threaded a die onto the bolt past the cut line before cutting it to length. Once cut, I bevel the end of the bolt on a grinding wheel. Remove the die and then run it through a wire wheel. Using a die instead of a nut will allow you to get a cleaner cut on that inital thread at the end of the bolt.

[Random Thoughts Racing]

x2 on this method. Thread the die on backward for best results.

I've always threaded a die onto the bolt past the cut line before cutting it to length. Once cut, I bevel the end of the bolt on a grinding wheel. Remove the die and then run it through a wire wheel. Using a die instead of a nut will allow you to get a cleaner cut on that inital thread at the end of the bolt.

[Bill]

Also useing a die grinder heats it up and may change it`s hardening strength.

[CRAIGHALL]

I'd rather use a nut instead of a die as the threads are already there. Some dies are sharp and may actually cut the root of a bolt deeper than the initial thread rolling or cutting.

[Scott_F]

I agree with Craig. even without a nut, if you make a clean cut with a cut off wheel, you can easily dress the threads with a thread file or triangle file. A slight chamfer on the end is the finishing touch. For extra points you can chuck the bolt in a lathe and face off the end.

[FABRICATOR]

Sawing is arguably the best hand method as it is the least disruptive to the bolt's metallurgy and plating. The bolt tip can be cleaned up and slightly chamferred with light grinding. The only time you should need to run a nut down the bolt thread before cutting, is to help hold the bolt for the procedure. A nut should not be used to reshape anything or clean out the thread groove because it simply can't do a thorough job and may in fact damage other areas of the thread or plating. The groove needs to be deburred using a 60* file or thread file before anything is run over it. If done carefully, a bare fine toothed hack-saw blade held at an angle by hand can also work pretty good for deburring. The job can be finished up by localized wire wheel brushing.

[FABRICATOR]

I felt like shortening a bolt today, and I don't know why.
For some cardio, I chose a tough as hell 5/8" aerospace fastener. A snug fitting nut and a leather glove were used to hold the bolt in a vise so it wouldn't get damaged. It took 2 new industrial quality blades to get through it. Cut was made dry so there wasn't oil all over for the blingy photo shoot. I prefer a disc sander about 10 to 1 over a grinder for just about everything, even when the disc is completely worn out and jambed solid from woodwork. Cut with saw, deburr with saw blade laid down so face of teeth match thread angle, and no, this is not a very fine tooth blade as mentioned. Dress end of bolt, chamfer, lightly brush with SS wire wheel. This is all that is necessary. With this method, even a Class 3 nut will glide off and on every time. With another minute or so of hand sanding on a flat table, the end surface finish would have been glass smooth. This brute took nearly 20 minutes to shorten, at least 10 of which were spent sawing.

[025]

Nice!! Is that bolt inconel?

[Haycock]

i have found that a band saw works well then a belt sander to chamfer it

[FABRICATOR]

Thanks! I believe this one is Inco.

Now matter how you slice it, sanding is good. :)

[mfs]

i like to use the bandsaw and ill clamp on to the hex of the bolt with vise grips and use a peace strap/plate to put under the bolt to make up for the hex part hanging down and make it level so the cut is more sqaure and then i use a push block on the back of the bolt. the vise grips will rotate and hit the table and that helps keep the bolt from spining, then i take it to the sander and first sqaure up the cut and then chamfer it.

thats how i do it at my shop but i all ways thought it was mickey mouse and their should be a better way... so this place i worked at... i had alot of time to do whatever as long as it was to help the shop and i had noticed that eveyone had a hard time trying to cut down bolts and they did it alot, so after wacthing these guys there (that never used a band saw before) lanch bolts across the shop.....i milled these v's in 2 plates of aulm and it had a pocket i milled in it to clear the hex on the bolt and u could clamp the bolt in between them and cut them easy in the band saw. they had one of those roll in vert. saws so u could just line it up clamp it and let go and the saw would cut it. it worked good.

[mfs]

this guy i used to work with had a cool little trick he would put all the bolts he cut down in a hole he pooked in cardboard and paint the ends that he cut off so they wouldnt rust and the cardboard would keep u from getting overspray on the rest of the bolt

[CRAIGHALL]

Best I saw was a thin cutoff wheel in a tool& die grinder and a simple vise on the regular magnetic table.

[FABRICATOR]

One thing to keep in mind with all of this is that with few exceptions, the stronger the bolt, the more suseptable it is to hydrogen embrittlement. Nearly all the commercial bolts and many aerospace bolts used in this sport are plated. Damaging or wearing out the plating along the shank or other stress areas can let this happen. If it slips or spins while clamped it can be immediately compromised. Some of those unexplainable fastener failures can be from this. The situation affects grade 8 and up, plated or coated.

[NicksTrix]

i like using a small machinist vise to hold the nut bolt combo and a vert band saw to cut them. using the vise holds the bolt snugly and helps keeps your fingers out of potential harms way if the bolt wanted to hang... it makes a nice straight cut as well, so minimal end dressing is required.

i have like many others used a cut off wheel as well when needed, sometimes you gotta do what you gotta do.

[Superfab]

I saw the bolt to almost the correct length. Then I have an assortment of aluminum split sleeves to fit almost every size to 3/4" that I slide over the shank. Then I put it into the lathe chuck and the sleeve keeps it from damaging the threads. Then I face it to length and bevel the edge for a clean start. Any small burrs can be removed with a thread file.