Quote Originally Posted by Tenson View Post
coolant is meant to be quite powerful, isn't it? Enough to blast the swarf away I thought.
Coolant keeps things cool, if you add lubricant it can stop things sticking, maybe ease the tool through the metal somewhat. It washes the swarf away, but if you are end milling with only one nozzle you have to aim it high on the tool above the depth off cut. Coming down from above helps avoid any metal holding fixtures. Quantity is more important than velocity, without air in the mix it is a "flood" coolant.

Yes, you do see it used at higher pressure with multiple nozzles but usually the machine has a closeable door to keep it in. The door is plastered with coolant, nobody cares if the hoses leak a bit. Was the original nose better than the cheap Chinese version? I can't remember.