Gunner wrote:
On Sun, 05 Dec 2004 04:59:25 GMT, machineman
wrote:


Got a job in our shop right now that I wish would go away. Putting a
2-3/4" hole 8" deep through a block of 718 Inconel. Shoving a spade
drill through it takes a couple of hours(2-1/4") with a 1/2" starter
hole first. The spade drill inserts will be toast when done :-) The
turning and boring is slow but not to bad, 40-50 fpm. Also have to put
4 3/4-10 tapped holes in one end.
The set-up time is the real killer on this stuff, took a couple of
days to figure out the procedures. Hopefully no more glitches and we
can finish up the rest of the pieces.


Sounds like a job for EDM

Gunner

Unfortunatly thats not an option :-( Burn time on nickel alloys would
be pretty long, even if using thin tubing for an electrode. Plus the
recast layer would be pretty hard as well, probably really screw up the
inserts on the finish bore :-) Slow and steady on a good solid machine
does the trick, and hss tools seem to work well, just have to keep an
eye on them and resharpen as needed.