Need drill bit advice, again

[Reddinr]

I read through a number of drill bit threads and I have one of the jobber HSS assortments, from Shars I think. What I'm thinking about doing now is to buy some really great ($$$) drill bits for aluminum for 4-5 specific sizes that I use often. I am looking for advice on the best choice. The HSS ones I have seem to smear and stick to 6061, it seems regardless of feed, speed, pecking, lube etc. I've tried new sharp ones too. I've heard that plain, polished carbide is a good choice. 90% of the time I seem to be drilling for roll-forming taps for 6-32 thru. 10-32 machine screws. Typically the holes are only 1/2 - 3/4" deep, blind holes. Often there are many of them per part.

The drilling is done on a small (RF-45) mill with the parts clamped securely. Sometimes CNC, sometimes using the quill. I usually use WD40 or some aluminum tapping fluid I might have nearby.

So
118 vs 135 degree?
Parabolic?
Carbide?
Other considerations?

Please help me spend some money.

 

[Jimsehr]

I like parabolic. They get the chips out better,

 

[mikey]

Odd. I use HSS drills for drilling aluminum all the time and have no issues with galling or a built up edge. I usually use 118 degree jobber or screw machine drills, WD-40 and have had no problems. I use drills from Triumph, PTD, Dormer and Cleveland mostly. I use roll taps a lot in aluminum and don't understand why you're having issues. Maybe buy good drills?

 

[Reddinr]

Thinking about it some, it is only the small holes that give me the problems I'm describing. I appreciate your insights.

 

[Bill W.]

You might also try Tap Magic for Aluminim... have had good results with it...