Cobalt alloys for lathe tooling

[Jeff.64]

I guess the part that I'm confused about is this part of the recommended use "best cutting properties are located at the surfaces of the casting."
The diamond holder presents a ground surface for the cutting edge, not the cast surface.

 

[woodchucker]

I guess the part that I'm confused about is this part of the recommended use "best cutting properties are located at the surfaces of the casting."
The diamond holder presents a ground surface for the cutting edge, not the cast surface.

not really the 4 sides are the surfaces. They remain untouched, only the end is ground like they want. The orientation is such that the surfaces are hard, and are providing the integrity in the cut. The diamond presents 2 sides to cut, and the top is also a cutting edge, but it is the hard sharp sides that in this case doing the cutting. Imagine if you dished the top (end of blank), those raised edges are doing the cutting. In this case they are not raised, but they are that hard surface they want you to keep. Like a knife edge presented up.

 

[pontiac428]

Crobalt, Stellite, and Tantung are all non-ferrous cast cobalt steels typically called stellites. T15 (aka Rex, Vasco Supreme, Panther 5) is tungsten steel with 5% Co with 5% V for high red heat and high abrasion resistance. A little different, but both good groups of steel. The steel blanks I just named are the reason I don't use inserts for routine work on my lathe.

 

[Jeff.64]

not really the 4 sides are the surfaces. They remain untouched, only the end is ground like they want. The orientation is such that the surfaces are hard, and are providing the integrity in the cut. The diamond presents 2 sides to cut, and the top is also a cutting edge, but it is the hard sharp sides that in this case doing the cutting. Imagine if you dished the top (end of blank), those raised edges are doing the cutting. In this case they are not raised, but they are that hard surface they want you to keep. Like a knife edge presented up.

Thanks! I guess I got hung up on the as cast surface part.

 

[ChazzC]

Thanks! I guess I got hung up on the as cast surface part.

I’ll ask my contact for clarification: the bits I purchased from Eccentric Engineering are ground on all 6 sides (and the round ones look to be centerless ground) - see post #3.

 

[ChazzC]

Crobalt, Stellite, and Tantung are all non-ferrous cast cobalt steels typically called stellites. T15 (aka Rex, Vasco Supreme, Panther 5) is tungsten steel with 5% Co with 5% V for high red heat and high abrasion resistance. A little different, but both good groups of steel. The steel blanks I just named are the reason I don't use inserts for routine work on my lathe.

As I noted in post #5 I regularly use T-15 inserts fri A.R. Warner.

 

[RaisedByWolves]

I’ll ask my contact for clarification: the bits I purchased from Eccentric Engineering are ground on all 6 sides (and the round ones look to be centerless ground) - see post #3.

Most likely true, but that is only to shine them up as “as cast” would look like absolute hell and turn people off.


Think cast a little oversize and ground to size, but that size still leaves plenty of usable surface with the correct properties.

 

[woodchucker]

Most likely true, but that is only to shine them up as “as cast” would look like absolute hell and turn people off.


Think cast a little oversize and ground to size, but that size still leaves plenty of usable surface with the correct properties.

yep, some of my old Rex looks a little awful not ground.. Works great, grinds nice.

 

[accokeek]

Many thanks to ChazzC in particular for providing a contact point and rough costs of CROBALT tool blanks. I have reached out and as soon as a price for the 5/16" round blanks is confirmed will order same. Also thanks to all others that shared their experience and thoughts. I'm a bit late replying to all these notes as I'm recovering from surgery and a bit slow, but looking forward to experimenting (AKA "playing") with cast cobalt tooling

 

[ChazzC]

Many thanks to ChazzC in particular for providing a contact point and rough costs of CROBALT tool blanks. I have reached out and as soon as a price for the 5/16" round blanks is confirmed will order same. Also thanks to all others that shared their experience and thoughts. I'm a bit late replying to all these notes as I'm recovering from surgery and a bit slow, but looking forward to experimenting (AKA "playing") with cast cobalt tooling

Da nada

I still want to give them a call to discuss using 5/16” square blanks for conventional bits