What is the function of the grease which sometimes fills or partially fills dies, and how does it "escape" onto the die faces?
Good question, I really don't know although I am suspecting that if no grease is applied, it can be possible that the coins can get stuck to the die and hence you get bizarre double strikes and other errors?
Just imagine - there are literally hundreds of parts in a coin press. And when all of them are moving they are pumping out 800 to 1,000 coins a minute - that much movement, that fast, requires a lot of grease. And when something is moving that fast, it is logical to assume that some of that grease may fly off certain parts, and some of it may land on the dies.
I really don't know. But would suspect the metal sheets go down an assembly line and instead of rollers, they just grease the line with grease so the sheets of metal slide better. This saves electric motors for the rollers. Then the coins go down an assembly line which is greased so the coins just slide on to the trucks waiting for them. Many coins go throught a grease machine so they shine and then they can tell people they are special made coins called proofs. The Mint requires all workers at the Mint to grease thier hands so no money sticks there ACCIDENTLY. Floors near the exits are all greased so any robbers would just slip and fall and be easily captured. All windows are covered with grease so criminals outside can not see in. As I said, I really don't know.
It is my understanding that it is more than this. The dies themselves are intentionally greased because that helps the metal flow better across the dies and extends die life. The coining process is all about efficiency and anything that extends die life is good for the mint. If they weren't greased dies would wear/break all the more quickly.
Possible, but I don't think so CT. If the dies themselves were intentionallhy greased that would mean that the coins would have to washed after striking. They are not.
As GD said with all the "moving parts" and with the close tollerance's in between the parts the friction that it would generate the machines would literally melt the grease acts as a buffer or fills the space no matter how minute between the parts thus lessening the friction, like the motor oil in your car allows the pistons to slide up and down in the cylinders, now imagine your car with no oil. Thats my take on the question. John
I do know that the edges of American Eagle coins are greased before they are struck. I watched them do it on TV on a show talking about gold and the US Mint.