Caught myself arguing both sides of coolant vs mist today

I was reading through a thread on Practical Machinist and found out that some shops are running flood coolant on aluminum with zero issues while others swear by mist to keep thermal shock down. It blew my mind because I always thought flood was the default for aluminum, but apparently it depends on your tool coating and feed rate. One guy said he cracked 3 inserts in a row switching from mist to flood on a 6061 part. Has anyone else run into this split where the 'right' way changes based on who you ask?

3 comments

3 Comments

reese_hayes713d ago

Oh man, that's the thing about machining, nothing is ever as simple as you think. I mean, it's wild how two shops can run the same material completely different ways and both get good parts. It's like that with a lot of stuff honestly, like with cooking or working on cars. One guy swears by a certain oil or a specific temperature for steaks and the other guy does the exact opposite and calls you crazy for doing it the other way. I think it's because we all learn from different old timers or from our own mistakes, and once you find something that works you just stick with it. Maybe it's just me but I've noticed that pattern everywhere, not just in the shop. So yeah, the coolant vs mist thing is just one more example of how there's rarely one right answer for everything.

evahenderson3d ago

Exactly lol it's like there's no real gospel in machining just what works for your setup

irisowens3d ago

Had a buddy who switched from mist to flood on his Haas. Ran a whole batch of 7075 parts. First three came out fine. Fourth one? Insert shattered. Chip welded itself to the cutter. He spent two hours chipping that mess off. Turned out his mist setup ran way lower pressure than the flood pump. The flood coolant was just hitting the tool differently. He switched back to mist and never looked back. His old man always ran flood on everything, but that guy retired in the 90s.