Shortening bolts

Thad Swarfburn III · Jun 24, 2009

Yesterday I needed 8 M10x16 socket head cap screws toot-sweet and all I had to hand were some 20mm long ones. While I was shoving the first one thread-first into the grinding wheel, one of the other guys asked me if I wanted to see a better way of doing it. Would I?

He chucked an angle grinder cutoff disc in the tool and cutter grinder, put the SHCS in a collet, and fed the wheel through the bolt. Beauty! A nice clean cut and I only needed to do minor dressing to clean up the threads. Safer too, as long as the T&C grinder doesn't exceed the max speed of the cutoff disc. Just make sure the disc enters the bolt in the V of the thread so it doesn't want to wander off course.

I know most HSMs don't have a T&C grinder handy, but the wage slaves amongst us may find this handy!

tel · Jun 24, 2009

My own favourite winkle for this job is to use a threaded, spilt bush in the 3 jaw - just chuck it up with the head inward and turn away the unwanted bit, you can also dome and polish the bolt end at the same time if that's needed.

steamer · Jun 24, 2009

tel said:
My own favourite winkle for this job is to use a threaded, spilt bush in the 3 jaw - just chuck it up with the head inward and turn away the unwanted bit, you can also dome and polish the bolt end at the same time if that's needed.

Yup...that's how I do it!....Just a bush sometimes with a shoulder to seat against the chuck jaws.

Takes about 5 minutes to make....When your done, drop the bush in the box you keep that size screw in for the next time....pretty soon you will have a collection!

bentprop · Jun 24, 2009

I'm just a bodger ;DI use a piece of plate,with a hole of the required diameter tapped in.For smaller sizes whack it with a cold chisel,and clean up on sander.Larger sizes need the angle grinder to shorten,and same treatment on the sander to clean up.

steamer · Jun 24, 2009

Whatever way that gets the bolt in the hole is right! ;D :big:

Dave

lugnut · Jul 9, 2009

I don't remember where I saw this idea, I'm sure it was someone on this board. I made this little sawing jig to shorten bolts and it works great. I used a piece of 1/4 X 1 1/2 flat bar about 7 inches long and drilled and tapped a collection of all the bolt sizes that I normally use. I screw the bolt to be shortened into it's proper hole until the portion needed be removed extends out the back side, and then saw of the excess with the band saw.
Use it all the time and wonder why I have not always had one.
Mel