Lard is a great cutting lube, active ingredient is lard oil, [olein], which is sold commercialy as a cutting fluid. Our foreman Frank used to mix it with kerosene, 50-50 when I was an apprentice for machining dural. Mineral oils don't make good cutting lubes for soft metals like aluminum or copper as they seem to flow away from the action.
I have seen soap/water and even gasoline [
] used to machine soft copper, and even had one guy who reckoned milk was the answer- till it went off in his suds tray! Nothing quite as permanent and truly obnoxious as really rotten milk!
Point is, these items are all at the supermart and I bet they are a tenth of the price of fancy cutting oils.
