[SEL] OT lathe tooling for copper facing.

[Rob Skinner]

On Jan 12, 2007, at 7:22 AM, Curt wrote:

> Fellow machinists, a lathe tooling question for you.....
>
> When using carbide insert tool holders, how does one determine when  
> to use negative rake vs. positive rake tool holders?
> Are triangled inserts the best for facing? Or would round be  
> better? Or some other shape?
>
> MSC doesn't have a lot of small clamp style indexable tools. The  
> shank will need to be 7/16 square with an overall length of 3".
>
> Will be facing copper samples in our lab here at work. Want the  
> smoothest, brightest surface possible to lessen hand polishing  
> after turning.....
> Curt Holland

Hi Curt,
Are you dead set on carbide?  I'd use a high speed tool, give just a  
little less rake than negative, generously round the point, hand hone  
the tool so it's razor sharp, and use a lot of cutting oil.