Ran a 1/4 inch endmill dry vs flood coolant on 6061 aluminum last week and it wasn't even close

I was roughing out some parts for a rush job and my coolant pump crapped out halfway through the shift. Decided to just send it dry with compressed air and see how long I could go. The chatter and heat buildup was brutal after about 10 minutes, plus the finish looked like garbage compared to when I got the pump running again. What do you guys do when your coolant system goes down mid-job?

4 comments

4 Comments

gracec161mo ago

Tbh dry cutting 6061 is completely fine if you know what you're doing. I've run entire jobs without coolant because the customer didn't want any mess on the parts, just some compressed air and a good chip evacuation strategy. The chatter you got was probably from feeds and speeds being too aggressive for dry conditions, not the lack of flood. Drop your RPMs down to like 8000, bump up your chipload a bit, and give it a nice mist of air blast. The finish can actually be smoother dry because you don't get that thermal shock on the cutting edge that causes microchipping. Plus flood coolant just makes a sticky sludge with aluminum anyway, which clogs your filter bags twice as fast.

wade8711mo ago

Started dry cutting 6061 once on a rush job and my air compressor died halfway through. Ended up using a leaf blower from the shop to clear chips, looked ridiculous but it actually worked until the air came back.

parkerbrown1mo ago

oh yeah, the air blast is the real MVP for dry aluminum. I started doing that after a coolant pump died on a friday and never went back for most of my 6061 jobs. that thermal shock thing is real, once i backed off the speeds a bit the finish actually got better than with flood.

margareto261mo ago

@wade871 that leaf blower move is genius honestly, I might steal that next time my air craps out. And @gracec16 I get what you're saying but respectfully I've tried dry cutting 6061 a bunch of times and it's never worked as well for me as flood does. Maybe it's my machine or my technique but the finish always comes out dull no matter how much I adjust speeds.