Trying to turn stainless steel taper.

[FTlatheworks]

I have been cutting a tapered hole in tool steel and putting it in my headstock and tailstock chuck. I then place a ball bearing in between the work on both ends and drive it with a lathe dog. I’m only turning 1-2 degree tapers. Lately it is chattering and tearing the metal. Can anyone help me out with this.

 

[davidpbest]

What kind of tool are you using to cut the material? And are you cutting stainless or tool steel? I don't understand your setup as described. How about a photo?

 

[FTlatheworks]

I will when I get back to the shop in about 30 minutes.

 

[FTlatheworks]

I have been cutting a tapered hole in tool steel and putting it in my headstock and tailstock chuck. I then place a ball bearing in between the work on both ends and drive it with a lathe dog. I’m only turning 1-2 degree tapers. Lately it is chattering and tearing the metal. Can anyone help me out with this.

I’m cutting stainless 304 with a carbide insert. Ccmt insert in a straight shank.

 

[benmychree]

How long and what diameter is the part? perhaps a positive rake insert with small radius and sharp cutting edge may help, also switching to 303 SS would help with tearing and chatter.

 

[FTlatheworks]

How long and what diameter is the part? perhaps a positive rake insert with small radius and sharp cutting edge may help, also switching to 303 SS would help with tearing and chatter.

I cNt get 303 where I’m at unless I order a huge amount.

 

[benmychree]

I cNt get 303 where I’m at unless I order a huge amount.

Try McMaster Carr

 

[markba633csi]

A super sharp, well supported HSS/cobalt tool should be able to cut it if you are able to grind bits yourself
Stainless is challenging because it tries to work harden if you don't take aggressive cuts
-M

 

[benmychree]

303 stainless does not have much tendency to work harden and can be cut nearly as fast as CRS.

 

[FTlatheworks]

303 stainless does not have much tendency to work harden and can be cut nearly as fast as CRS.

I wasted so many tools tonight. It must have work hardened cause I was taking some monster cuts just making everything concentric and taking off material before tapering the part to the final specs.