parabolic drills

[Rekd]

Originally posted by E-Stop Parabolic drills have a wider web to allow better chip evacuation and coolant flow. They work great on aluminum but if you are only drilling 3/8 thick 6061 plate, I doubt that you will notice any significant difference. Another option is the solid carbide 3-flute drills (I like SGS brand). You can really plow through aluminum with these drills when drill 2XD or less. HuFlung -- you say that he is going to need to peck anyway to chip break. Do you really think that is necessary on 3/8 thick material? I wouldn't unless the hole size is less than, say, 3/32 or so.

+1 on the 3 fluters. You can almost RAPID thru the part with those sucka's

Also, Agreed on the pecking in 3/8 with anything less than .100 or so.

'Rekd

[Machine1]

So what kind of C-SP should I start out with using the parabolic drill. I am using .1285 - .438. Any suggestions would help

[Rekd]

I would start around 600-800 and work your way up. The bigger the tool, the heavier the chip load. I've run para's in alum at over 1400 SFPM with good results.

'Rekd

[Machine1]

You must of had some incredibly high spindle speeds?

[Rekd]

I believe I was running a drill just over .500 dia, at around 9,500 or 10,000 rpm. I was going like .750 deep, no pecking, feeding at like 125 ipm.

You could barely see from the steam. The drill looked like it was rapiding into the hole. The chips were around .015 thick. It was beautiful..

'Rekd

[Machine1]

Thats awesome!

[Partier SP]

I was Googling around and came across this thread.

I'm looking at running some small parabolic drills into some 316 Stainless. Any idea on how affective this would be? The size I'd be using would be a #32 drill (0.116"), drilling to a depth of 1.300".

Everywhere I look I hear these are great for aluminum, but I was hoping that the parabolic design would help with chip extraction due to the depth of the hole.