# cuttin HSS



## hopeless (Jan 21, 2012)

Hi all you learned people I need some help ( a lot really :big I have two 3" pieces of HSS steel that I need to cut in half to fit my tangental tool so it dosen't foul the works. Is it able to be done without special tools/cutters? I usualy use HSS as supplied and grind to suit the jod so this ia new to me.
Pete


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## TroyO (Jan 21, 2012)

It may not be the "right" way but I usually grind a notch in it on the grinder using the corner of the wheel then clamp one end in a vice and after covering with a shop rag I smack the other end with a hammer.

It works, but I think using a dremel cutoff wheel at least for the grooving is probably safer and likely to lead to a better cut.


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## Lew Hartswick (Jan 21, 2012)

I "pre-shape" some lathe tooling HSS bits with an abrasive "chop saw" . No problem.
So just chop it in two. 
  ...lew...


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## bvd1940 (Jan 22, 2012)

I use a air die grinder with a 3 inch Norton OBNA2 cut off wheel, cuts like hot butter


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## Jasonb (Jan 22, 2012)

Cut of wheel in a Dremel will be OK on small section like that.

J


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## steamer (Jan 22, 2012)

I've use all of the above at least once....if your just making it smaller, +1 for grinding a notch in it....a narrow wheel will keep the amount of stock ground off to a minimum, put a rag over it in case it shatters....it never has on me.....but you may be the first...and give the piece sticking out of the vise a clout with a hammer. It tends to be brittle as it has a Yield strength in the 500,000 psi range and an Ultimate strength in the 550,000 psi range....so nearly NO ductility....

It usually breaks right at the notch.

WEAR YOUR GLASSES! 8)

Dave


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## hopeless (Jan 22, 2012)

thanks guys I knew I could rely on the forum to come up with ann answer
Pete


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## Ken I (Jan 22, 2012)

The Dremmel cutting disk works but slow. The notch and snap method works (wrapped in cloth).

Nowadays I just use a 5" angle grinder and a steel cutting disk and chop it right off.

Safety glasses or full face mandatory.

Ken


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## Dave G (Jan 22, 2012)

Be very careful when breaking HSS. It has tendency to splinter into multiple pieces and at high speed. I will share with you something that happened to me about 20 yrs ago. While walking accross the shop floor on the way to our tool crib I heard a tink and felt something go through my hair. Parted me right down the middle but didn't touch the skin. I looked around to find one of the other tool makers looking around the floor for something. I walked over to him and asked what he was looking for and he said he had just broken a tool bit that he had mounted in a large planer that he was running. I told him what had just happened and his face went white with fear. The trajectory and speed of the piece of HSS was like a bullet as I heard it hit the back wall of the shop a few milliseconds after parting my hair. After many apologes we sat down and figured out another way to do the job he was trying to do without leaving the tool hang out too far. If I would of been a couple of steps ahead of where I was when this happened I probably wouldn't be here today. I am convinced it would have hit me in the forehead and it wouldn't have been very pretty. We kept this to ourselves to keep him from the embarassment and the bosses wrath but he never let the tool bit hang out of the holder again. He took the time to do the job right after that. That was the last day that I wished I was taller and have been happy with my height ever since. LOL I have seen broken drill bits fly 40 feet accross the tool room without hitting anyone, I have seen shafts being ground in an OD grinder thrown out of the centers and hit the ceiling of the shop before. These occurances have caused me to be real cautious when I work, not only can accidents in the shop cause injury but I am convinced some accidents can be fatal. Probably not a big chance of serious injury by breaking HSS as others have described but I won't be doing it. Use an abrasive cut off of some kind and sever the piece completely is my advice. Sorry for the rant but safety comes first. When reading this post and the responces my hair stood up on my back and I felt compeled to tell this story. Work safe, Dave


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## Lew Hartswick (Jan 22, 2012)

Like Dave G says, I don't believe in "BREAKING" things that can be CUT. 
There just too many thing that can go wrong. (including ruining the piece)
  ...lew...


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## Swede (Jan 22, 2012)

I agree with the warnings re: breaking HSS, but I think it can be done with total safety so long as one doesn't do something foolish like make a tiny notch in a 3/4" square HSS blank and expect it to cleave cleanly. 3/8" on down, no probs. The cotton cloth is a correct way to do it.

A good break can be made in a lathe bit by using a dremel wheel and cutting a line on all four sides so they connect. This keeps the break more square, IMO.


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## ncollar (Mar 17, 2012)

The quickest way I found is to place the HSS in my shop vise then take a piece of pipe that fits as close as possible then slip it over the exposed piece and give a sharp blow with a hammer holding the tubing that has the 2nd half.
There is always more ways than to skin a cat.
Nelson Collar


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## mzetati (Mar 19, 2012)

A very thin cutting disk on the angle grinder, paying a lot of attention into cutting at any angle but square.
I'm lazy. ;D

Marcello


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## hopeless (Mar 19, 2012)

with all the tips coming it gives us newbies more help all the time.
As the instigator of this thread I was wary of the groove & snap method so I cut all the way through with a dremel. I guess being new to HSS I played safe but without the helpful tips here I would still be wondering how to do it 
Thanks guys
Pete


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## Ken I (Mar 20, 2012)

The notch and snap method (wrapped in cloth to contain shrapnel) is less than desirable but I will admit to doing it on occasion.

If all you have to hand is a bench grinder then you are pretty much forced in this direction.

An angle grinder with slitting disk is the way to go.

As your own motto states "If you only have a hammer....."

Ken


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