I think running coolant through the spindle is overrated on most jobs

At the shop I work at in Cleveland, everybody acts like through-spindle coolant is the only way to get a good finish. I've been running these 304 stainless parts for a client the last 3 weeks and I get better results with a good high-pressure external nozzle pointed right at the cut zone. Less mess, less waste, and I don't have to worry about the coolant lines clogging up inside the spindle. Has anyone else found external coolant actually beats through-spindle on certain materials?

2 comments

2 Comments

oliver_fisher1mo ago

Is it really that serious? I mean, I get that through-spindle coolant is a big deal for some guys, but it's not like you can't get a good finish without it. I've seen plenty of jobs where external coolant works just fine, especially on stuff like 304 stainless where you need to keep the chip flow going. People act like the spindle's gonna explode if you don't have it, but it's just more parts to fail and more time cleaning lines.

cameron_webb1mo ago

Yeah but nobody's talking about how through-spindle coolant changes the whole dynamic with gun drills and deep hole work, @oliver_fisher. Without it you're basically stuck with peck cycles and praying the chips don't pack up on you at the bottom of a 10x diameter hole. External coolant just can't get the same pressure and volume down there, so it's less about finish and more about actually making the feature without breaking a drill.