Stupendous Man wrote:


(snip)

Whups. End view, It would take a real pair to plunge with this one.
http://i221.photobucket.com/albums/d...e/IMG_0882.jpg

Yup, it's a trepan, I've used them but "never" to work at that depth.
Manchester makes curved support blades for inserted tooling, I don't
know if Iscar does or not.

Most often trepanning is done for a support/location lip or face seal
using "O" rings.

Used to be you could get tool steel trepanned, die blank with a hole in
it, they kept the inside, you got the blank with a large starter hole,
for the same price as the solid plate. Expensive material saved, labor
saved, win-win.... Who said "GREEN" was a new thing.

Matt