Carbide inserts tool holders.

Another question for you the carbide tool holders that you can buy are they hardened.

Would I be able to mill a 16mm holder down to 12mm to fit in my quick change tool post holders.

Edited By Dave Harding 1 on 15/06/2019 23:56:39

You sure can! I've done this plenty of times.

Cheaper holders will be easier than high end ones though.

Jim

You sure can! I've done this plenty of times.

Cheaper holders will be easier than high end ones though.

Jim

Hi Dave,

On the few holders I have come across I was able to mill the holder down using a carbide tipped cutter, would probably be possible with a HSS cutter but the edge might need grinding afterwards.

Thor

As Jimmy says you may be able to machine the cheaper ones but a named brand may be harder, I've taken the corners off a set of face mill inserts trying to tale a good US brand holder down in thickness.

The cheap ones I've had aren't very hard they are no harder than say a high tensile steel bolt.

I tried with a Sandvick holder, gave up in the end it was so tough. I am sure the cheaper holders would machine ok because I doubt they are as tough.

Dave W

I always try to buy 20mm holders and then mill them down to 18.53mm which is the exact height of the Smart & Brown model A which I use.

I have milled down at least 25 down, including Kennametal, Stellram, Sandvik, Iscar, Korloy, Seco, and others including Chinese, and they are all similar hardness. I use a Ceratizit 50mm shell mill with 5 RPHT12 inserts in it. The inserts can be indexed six times per set, and milling down just one tool uses up an index.

If you only have hss, then keep a good flow of coolant and use a very slow speed.

If you have the relatively simple chinese holders I have then it may just be easier to make some extras to fit wider and other tooling

I bought an inexpensive set of 10mm insert tool holders from Aliexpress. They were a bit tough to machine down to 3/8" to fit the Myford using HSS in the lathe, holding the tool holder in the four jaw chuck. HSS tool kept skidding over the surface instead of cutting.

Carbide end mill whizzed through it like cheese, holding the cutter in the lathe chuck and mounting the tool holders in the toolpost.

So, harder than mild steel but not super hard, but certainly a bit tough.

I failed even using carbides to make a dent in it. Its probaly easier to make a tool post holder to accept a 16mm tool.

A job for the weekend.

Yes agreed. The cheap ones are quite easy but I had to use a carbide mill to cut down a Sandvik holder for a mate. Tough going but I got through it.

You could try annealing them. Heat them up and let them cool as slowly as possible.

I took them to work and popped them on the Bridgeport mill a couple of minutes and it was done.

That's how you harden many of the better Tool Steels :D

I have on order from China a 25 X 25 toolholder for 22 size carbide threading inserts. The 20mm holders only go up to the 16 size. So I will have to reduce the height by 6.47mm to fit the lathe, I'm not looking forward to doing it.

Dave, your carbides must be made from HTC (high tensile cheese) bin them now.