How cutting fluid works (newbie question)

If it does indeed solidify under pressure, then it might stick to the cutter in preference to the work, or something, and allow some flow, and so forth. But grain boundries doesn't seem plausible, as oil doesn't leak out of your car's castings! Not counting splitting of course, which I can easily visualize, having whittled on wood before.

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

For oil to leak out of a casting, the spaces between the grains have to be continous over the entire thickness of the casting, so the fluid can percolate, right?

In the case we're discussing, the behavior near the cutting edge of a metalworking tool, the distance scale is much much smaller - more like a thousanth of an inch or less, vs a half or quarter of an inch.

If you made an engine casting with a two mill wall thickness, you *would* have to worry about oil percolation through the grain boundaries.

Jim

ONE purpose of cutting fluid is to assure that the tool and work are

Dan Mitchell ============

Cast iron is indeed porous to oil. Many old castings are soaked with it!

Dan Mitchell ============

I trip it on using a large hypodermic and a #16 needle. Obtain from a rural pharmacy or a vet supply. There was an article in HSM some years ago on building an electronically controlled, solenoid actuated pump unit that would do this. It's on the to-do list but ....

Drop-at-a-time is much cleaner and less mist-ifying than either flood or mist.

Ted

As anyone trying to TIG on one will quickly discover. :-(

Ted

I've found this to be especially true with aluminum.

Ted