Unpopular opinion: I was wrong about coolant ratios for years until a shop in Tacoma showed me their setup.

I was visiting a buddy's shop up there and saw them mixing their coolant at a 12:1 ratio for aluminum, which I always thought was way too lean. They ran a test cut on a part I'd been struggling with and the finish was perfect, with no built-up edge at all. What's the thinnest mix you've successfully run on stainless or titanium?

3 comments

3 Comments

robin_bennett781mo ago

Honestly, 12:1 on aluminum sounds crazy thin to me. I tried a 15:1 mix once on some 6061 and it just smoked and welded the chip right to the tool. Maybe their machine or toolpath is doing the heavy lifting. For stainless, I wouldn't go past 8:1, you need that lubrication.

robertgreen1mo ago

What test did they run to check the finish?

the_cole1mo ago

Hey @robertgreen, wasn't there a salt spray test for that? I remember reading they put it in a fog chamber to see how long the coating holds up.