Overheard a shop supervisor say dry running is fine for aluminum and I got skeptical

Was at a job fair in Houston last week and this older supervisor was telling a new hire that you don't need coolant for aluminum roughing passes on a Haas VF-2. I've been running my own small shop for 6 years and I always use at least a mist to keep chips from welding. Has anyone else heard this approach actually working long term or is that guy just asking for built up edge problems?

3 comments

3 Comments

nathan85123d ago

Had a buddy who tried this exact same thing on a VF-2SS running 6061. First few passes looked okay, chips were blue but not horrible. About twenty minutes in he noticed the finish getting rough, then the endmill started squealing. Pulled the tool out and the flutes were packed solid with welded aluminum. Ruined the tool and the part. He said it took him an hour to chip all that built up edge off the insert pockets with a pick. He runs mist now on everything except maybe a quick facing pass with a ton of DOC.

jade_grant9523d agoMost Upvoted

What feed rate was he running when it started going south on him?

faithbaker23d ago

Notice how it's the same damn thing with anything that gets pushed too hard. Seen it with lawn mower blades on thick wet grass, kitchen knife that's too dull to slice a tomato, even my brother in law trying to trim a hedge with scissors that aren't sharp. First few cuts look fine then suddenly everything binds up and you're fighting it. The material builds up, friction spikes, and now you've got a wrecked tool and a scrap part. By the time you feel it going bad, it's already too late. Most folks just need to back off 10% on the aggression and they'd save themselves a lot of headaches.