best drill bit for

[98ciHemi]

Re: best drill bit for

With Aluminum, high RPM is your friend. Loren's charts show 70-125 SFM for aluminum. At school we usually go 150-200 sfm. I would either step drill it or even better, use a combination drill/countersink (centerdrill) to start your hole.

[ch1ll]

Re: best drill bit for

Alright I'm blowing the top off here, I'm a Journeyman Tool and Diemaker (CNC Moldmaker actually). Listen to Chad. Slow and easy. Specially if your in your garage. You can blast away if you want (rpm and feed) but if you don't have flood coolant you'll load your tools. (cake?) Want a good cutting fluid, try parafin (TRADEMARK Boelube used exclusively by Boeing air craft company). Just grab a candle out of the house and rub it across the cutting edge. A little bit goes a long way and don't stink like kerosene or WD40.
Drill Doctors are really good when the occasion calls for them, but not all models are good as others. Some are better than others. Then again if you sharpen drills daily or any cutting tools for that matter, you would be supprised at how good you get at it. All you have to do is understand the cutting action and practice.

[Loren]

Re: best drill bit for

Hey, as long as I ain't the one paying for it, you can go as slow as you want. ;)

[IRONHEAD]

Re: best drill bit for

thanks guys..
I just want the holes straight.. and clean..
I get to practice on dads intake for boat..
before I do my intake for the 454..
I know.. not nice...
but his doesn't have to look good. so if I f up. it can be welded and redrilled if needed..
plus we have 3 sbc intakes ..
and my dart intake wasn't cheap... ;D

[Huskinhano]

Re: best drill bit for

I've drilled and tapped a lot of aluminum. I use either straight water or water with a little liquid hand soap mixed in. Works very well. Do not use oil! it will seize up right away. Not fun trying to remove broken drill bits and taps. One last thing. Use a good quality drill bit, forget any Chinese drill bits. They're just too brittle.

[SpiderGearsMan]

Re: best drill bit for

hole saw

[RR]

Re: best drill bit for

High speed steel, use tapping fluid,go slow and you should be fine. I would start with center drill since the surface you are likely drilling on an intake will not be perpendicular to the bit. Also, the better restrained the part, the better. Clamp it down! You should be fine. If you are going to tap the hole after drilling, I would drill 1/32 undersize and the final drill with the correct tap drill.

As for the drill data that has been given, I wouldn't worry trying to calculate that out for your application. This info is given in machining data books and is intended to optimize tool life. You are not going to be able to control feed rate well enough to make this useful. This usually also works best in production if the area is flooded with coolant to help remove heat and chips.

Aluminum does carry the heat away with the chip, which is usually long and stringy. Safety tip- Don't wear gloves or loose clothing while doing this!

What do you know. all that machining process experience finally came in handy!