OK, so I usually use whatever bits I can get on sale. I cut a lot of 6061 Aluminum on my converted BP. Because of the steppers on my conversion I can really only run 15 IPM and .25" Deep with a 1/2" End Mill at 3000 RPM with mist coolant.
So first question if I can only go 15 IPM 1/4" deep with a 1/2" HSS or M42 End Mill should I still be running at 3000 RPM?
Next question what out of the listed below would be the best bang for the buck taking into consideration cut quality and tool life? These are cheap imports. I'm not sure if HSS or one of the cobalts are better for Aluminum or is Carbide?
1/2" 2 Flute HSS $2.76
1/2" 2 FLute M42 $7.30
1/2" 2 Flute M2AL $4.70
1/2" 2 Flute Solid Carbide $23.00