We spent a day with Dan McMurray from Alpha Industrial Supply trying to break his tools. Bottom Line, we could have, but decided to stop once we hit 482 ipm feed rate in 32Rc 4140. You heard that right. Those sound like common feed rates for Aluminium, but it was 4140. We also slotted a 1/2” Endmill, 3/4” Deep in that same 4140, ran it at 47 ipm at 4800 RPM’s. The finish was incredible. Dan has been looking for machines he could really load up his tools on and show what they could do. He stressed that there best fitted for a CAT50 machine with a ton of torque. He was amazed that our little VMX24, CAT40 12k Spindle took it like it wasn’t even there. It wasn’t until we hit that 482 ipm that we got above 80% spindle load. Have a look.