How/where in minting process does the Grease Filled Dies impact the coins

Grease filled dies is a common error.

I've always wondered how the grease gets there?
How much grease (is it automated)?
What type of grease?
And Why (metal flow, slight cooling) ?
or are there two mint guys having a grease gun fight around the machinery?

So are there grease sprayers that spray every 1,000 hits? Or is it done manually at some point.

Essentially how, when and why does the grease get put in there.

Thanks

 

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Any " Die Setters " out there ?

 

Been...ahem...discussed before, let's see if anything new.

 

I twied a searcht butt fund nuttin'

 

The act of striking coins uses metal moving against metal, and I don't mean the planchet itself. This requires some kind of lubricant. There are ALSO tiny bits of worn metal flying around. Gradually, these tiny bits of metal and lubricants form a "slurry" or "grime" or the technical term, "yucky junk". Since raised letters of coins come from recesses in the dies, these are GREAT places for bits of "yucky junk" to coalesce. It's no more complicated than that. Once in there, they tend to hang around for a bit before falling out.

There is no "grease monkey" with a grease gun running wild in the mint.

 

Yeah, but it's the "some kind of lubricant" aspect of it I'm questioning. When, how often and how ??

There's no Mint Monkey squirting the grease in? Then how ?

 

Likely just a light machine oil.

 

You need to understand just how rapid fire these modern presses are. This is not like making a one-off medal at the old Carson City mint. These babies are firing so fast you can barely see anything happening other than blanks pouring in and coins pouring out. The heat generation alone must be quite a problem.

 

Maybe this one came out of that batch .

 

Now THATS a fun trio of words to say and ponder the deeper meaning

 

A grease filled die is similar to dried pieces of cookie dough that fill up part of a cookie cutter, and thus the recessed image clogs up and can not stamp what is on the cutter.

Grease attracts everything, including dust particles, and other small pieces of dried up grease (and whatever has stuck to it), and falls off from the force and repitition of striking. This can fill in die impressions and prevent raised details and lettering from appearing.

 

And once it falls off, if it stays on the die, we get a "dropped letter" error.

 

12 per second (up to 750 per minute) according to this article ==> http://www.coinnews.net/2013/09/20/how-the-philadelphia-mint-makes-coins-for-circulation/

But it never said anything about grease. So I was stumped as I was thinking maybe there was a lubricant bath to the planchets at some point but it seems it's from the machinery and invisible grease monkeys.

 

After the coins made in that video were finished, they didn’t have enough of them, so they made (wait for it) Samoa.

 

Can I have Samoa ??


So the girlscout cookies and their thin mints are (wait for it) Minted at the Mint ?

 

Boooo hisses!

 

Great video! I think it explains a lot.