Here is a video of a 3 flute Hi-performance endmill slotting aluminum 0.75" deep per pass.

Well, not entirely slottimg, more like pocketing, but the very first move is a full width slot.

Stepover is 0.4"

First i calculated the cut on HSMAdvisor.

Used 6061 aluminum as material and HP endmill at a tool type.

Tool torque and deflection limits were both set at 100% and performance slider was at maximum.

This is what it came up with:

S9127 RPM 125 IPM.

Full slot, 0.75" deep.

45 in^3/min mrr.

Looking at how easy it went i think i should allow for more load in my calculator.

If you have not yet tried HSMAdvisor, make sure you do.

You will be amazed at how much productivity you have been missing out on.