# Cutting HSS with Carbide



## Chewy (Oct 16, 2019)

I want to make a circular form tool out of a M2 HSS blank.  A 3/8 radius for the handles on the float lock vise.  I would like to make several for other projects.  Is there any reason that I can't tilt the blank 5 degrees and feed a 3/4 carbide end-mill into the corner of it?  There are some 4 and 6 flutes available on Ebay for around $40. Don't mine paying the price if I'm not going to ruin it. Any ideas about speed? I plan oh hand feeding it on a PM 30 mill.

Thanks inn advance!!!  Charles


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## Downunder Bob (Oct 16, 2019)

Never tried machining a HSS cutter with carbide, not sure if it would work or just shatter the carbide. During my time in the toolroom we always made profile cutters one of two ways. The choice would be determined by the best way to make the profile we wanted

1. using an already hardened HSS cutter we would shape it in a tool and cutter grinder, or

2. we would machine the profile cutter out of annealed HSS and then harden it, in this case a carbide tool would be used. the hardened cutter would then be finished profile ground in the Tool and Cutter grinder.


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## bhigdog (Oct 16, 2019)

Chewy said:


> Don't mine paying the price if I'm not going to ruin it.



You will and it won't take long.

Twer it me and I just needed a few handles I would make the form tool from almost any tool steel and torch harden it. .................Bob


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## C-Bag (Oct 16, 2019)

I've used a carbide die grinder and bit to grind radius on HSS in my homebrewed fixture and to make flats on HSS end mills to mount in arbors. Worked fine and didn't hurt the carbide bit at all much to my surprise. YMMV.


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## Downunder Bob (Oct 16, 2019)

C-Bag said:


> I've used a carbide die grinder and bit to grind radius on HSS in my homebrewed fixture and to make flats on HSS end mills to mount in arbors. Worked fine and didn't hurt the carbide bit at all much to my surprise. YMMV.



That's nice to know, I'll try that next time I need a profile tool. I would normally just use the dremel with suitable grinding wheels to get the shape I want, never thought to use a carbide cutter. 

I had an exciting experience a couple of days ago I using the dremel with a 1/8th shank carbide cutter to cut a profile in a piece of aluminium with a 35mm hole and I was working inside that holeI only had a one hand grip on the dremel and the cutter dug in ripping the dremel out of my hand it kept running and made a hell of a noise I quickly picked it up and switched it off. The shank was only steel, not solid carbide which would have snapped, but in this case it was bent about 30 deg. after straightening the shank i was able to finish the job. All is well that ends well.


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## C-Bag (Oct 16, 2019)

One of the best things I've done is make a solid mount for my big die grinder. MUCH safer. I don't know how many times I've been trying to enlarge a hole with a carbide burr and it started chattering the hole uncontrollably. With the grinder mounted this doesn't seem to happen. It's also opened up to use it for sharpening etc. I've quit using Dremel's because of the little shanks. I've gone to Foredom and 1/4" shanks when I have to freehand.


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## benmychree (Oct 16, 2019)

The carbide end mill will last quite quickly on HSS; if chips are made, they will be carbide chips (and chunks); I make such form tools on the corner of bench grinding wheels, or on the T&C grinder, or just machine them freehand and finish with a file.


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## mikey (Oct 16, 2019)

Instead of using a form tool, perhaps a radius cutter or gravers might be a better option.


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## Chewy (Oct 16, 2019)

Followup.  I tried the carbide burr on a 3/32" parting tool and it slowly worked.  Sketched radius and ground to the line.  Used carbide burr to clean up and give perfect circle.  I then mounted in on the lathe and turned a 7/8" diameter 1018.  Got a little chatter and sped up.  Got a really good cut, pretty smooth.  Really didn't need to smooth much. Never expected a flat parting tool to cut as good as 1/2" HSS tool. 
Bottom line is I'm going to downsize the HSS blanks I am buying and make permanent radius form tools to have on hand. A ball turner would be nice.  That is after I get a 5C collett chuck and D1-4 Face-plate.

Problem solved.  Thanks to everyone!!  Charles


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