Folx,

When having to hog metal on smaller mills (mine is Sieg X3) you will
sooner or later discover the HP limitation of our machinery.

When going with indexable EMs, cheaper variety uses negative geometry
- which requires lots of HP for decent metal removal rates. Going with
"solid" EMs - carbides and likes, is pricey and EMs don't last a lot,
due to lack of rigidity in smaller mills. That and the fact the RPMs
on these mills don't go into the area that carbides require (stock X3
is limited to 2000 RPMs).

Yet, there's a way to hog even toughest of tool and high-Cr steels.
Enter the positive-geometry inserts and indexable endmills.

The inserts have special tip design that provides for positive
geometry. Unlike negative g inserts, these can only be used in 2
positions before you discard them, but man do they remove lots of
metal in a hurry requiring very moderate HPs !

As always, Ebay is our best friend. I recommend looking for 3 flute
3/4 EMs. If you can get a kit (EM + 10 inserts) for under $100, it is
a killer deal and will last you a long time. Do consider availability
of inserts - google for replacements before bidding.

When ordering inserts, order them with larger "tip" radius - these are
stronger and will last much longer. For square shoulders and likes you
can always do a cleaning pass with regular EM.

On Jun 10, 8:13*am, rashid111 wrote:

When ordering inserts, order them with larger "tip" radius - these are
stronger and will last much longer. For square shoulders and likes you
can always do a cleaning pass with regular EM.

I grind HSS end mills that way and they do last a lot longer.
Any brand you'd like to recommend?