drilling super alloys

[Alan Alldritt]

Hi,
Do any of the engineering members out there know the name of the (or do they even still exist?) drills that were used on Inconel, Nimonic or other high nickel content super alloys?
They were triangular in section and slightly fluted and would only cut once reaching cherry red from friction when they would slice through like a hot knife in butter.
Drilling the single crystal alloys is done with lasers so perhaps they are no longer needed.
Thanks in anticipation
Alan

[Alan Cantwell 1131]

stallite drills, orrid stuff, eats carbide alive, wevspark errode much of our hi temp nimonics alloys, as a matter of interest, the tailplane leading edges of the tornado are inconol covered, drill by hand, wonder how many drills they went through

[Alan Alldritt]

Stellite drills - there the ones - thanks for that Alan

[Chris Lane]

Ah - you mean these things. I often wondered what they were for!

Chris

[Alan Alldritt]

That's them - I knew I hadn't imagined it all!
Alan

[James Stewart]

What rpm did they turn at to cut through those materials?

[Alan Cantwell 1131]

we ran 6mm ones at high revs, for us, 1800 rpm, important thing was the keep a fair even pressure, use no coolants, and dont bottle out when all goes bright red, thats when they start to work

[David Whiteley]

Have I misread things? Are these bits only good for one hole each? Expensive!

Dave

[Alan Cantwell 1131]

yup, but they do sharpen, but i have not used one for many years, if you wish, i will enquire with our tool guy, he has finger on the pulse with anything that comes on the market, so much is out there now,