Cobalt alloys for lathe tooling

[accokeek]

Just bought a pair of "diamond" tool holders for my lathe and was fascinated by videos of Crobalt tool bits. As usual this led me off to interesting byways on the Internet, but then I wonderedwaht are people's experience and/or opinions about using Cobalt alloys, such as CroBalt, Stellite or T15 for lathe bits (turnign, facing adn threads)

 

[woodchucker]

Stellite and Tatung G user here.. very hard, keeps a sharp edge, cuts like HSS, but holds the edge longer. Can cut harder metals...
I don't remember if I have done an interrupted cut with them.

Avoid thermal shock. It appears the cast alloys do not like it. Also keep the cutting edge close to the surface of the bit, do not grind it down much below the finished surface. The strength is near the surface.. can't remember where I read that.

 

[Nesse1]

I bought a set of diamond tool holders from Eccentric Engineering, and like them. The crobalt cutting tools like nice, and given a chance to do over, I'd have ordered a couple of pieces with my order. That said, one of the values of these tool holders is the ease of sharpening, including the sharpening guide tool that comes with the set. Unless you are cutting hard metal, I think the standard HSS tools are adequate. And they are easy to sharpen, when the time comes.

 

[Nutfarmer]

Stellite is a great cutting tool material. Hard to find now days. Holds an edge at higher temperatures than high speed steel.

 

[ChazzC]

I, too, have a set of Diamond Tool Holders (and included both square & round Crobalt blanks due to the shipping costs; however, the blanks are made in the U.S. so must be available here from somebody).

I also have a set of A.R.Warner tool holders and use their T-15 inserts in them. This perform very well and can be sharpened by just rubbing the top on a stone. They sell a range of sizes of inserts that will work in other holders as well, but their tool holders are very well made. Here's a comparison of A.R. Warner Tool Holders with others:

 

[GeneT45]

I have a couple diamond tool holders from back when they were sold by Bay-Com. They rarely see use these days. They're pretty good, but not as good as learning to grind HSS in a conventional fashion.

Gst

 

[accokeek]

Many thanks for your inputs on using cast cobalt alloys for turning tools. I think my next chore is to find a US-based source for both square and round tool blanks, so that I can do my own experiments, Any suggestions about where to buy to buy CroBalt, Stellite, Tantung or T15 tool bit blanks? I many itmes find recommendations superior to "googling the net"

Thanks again

 

[ChazzC]

My spare bits came re-packaged, so all I know is what they say:



I don’t use Google more than necessary as they know enough about me without giving them more access (I use Safari, and at least Apple leaves me alone). However, a search for “crobalt tool bits” yields this website:

Crobalt® Cast Super Alloy

Crobalt® is a high Cobalt based cast alloy, non-corrosive cutting and wear tool material used to produce standard sized or special tools per customer blueprint.

crobalt.com

which lists a range of sizes of blanks. I tried calling the numbers but got a message that they were closed and to leave a message. D&B says that Illinois Carbide operates under a different name.

HSM has 5/16” round blanks, but the square blanks are backordered:

Tools « Machinist's Resources « Metalworking « Storefront « VP

You can try calling them or calling Gary at Eccentric Engineering and see if he’ll tell you where to get them.

 

[Nesse1]

Many thanks for your inputs on using cast cobalt alloys for turning tools. I think my next chore is to find a US-based source for both square and round tool blanks, so that I can do my own experiments, Any suggestions about where to buy to buy CroBalt, Stellite, Tantung or T15 tool bit blanks? I many itmes find recommendations superior to "googling the net"

Thanks again

Maybe post up a WTB thread? When I asked for some HSS blanks a while back, several members here made really great offers. Some cobalt blanks too. I bought a pile of cutting blanks for very fair, darn cheap, prices.

 

[ChazzC]

I made contact with Illinois Carbide this morning and followed up with an email asking about buying small quantities of Crobalt® tool bits (in my case, 1/4" Round & Square for the Diamond holders, 5/16" for general use and a couple of Cut-Off Blades). I'll post results here.