Webbing question

[kurtrr]

My question is about the size the the blanks cut from the sheets. I would think the blanks would be a bit larger than the coin and the upsetting mill would reduce the diameter to a bit smaller than the coin when making the planchet. Is this the case?
webbing.jpg

[MintErrors]

Planchets are typically 0.2mm or 10/1000 of an inch larger.
The size of coins were pretty much standard through many design types.

[kurtrr]

I thought planchets had to be smaller to fit in the collar of the coining chamber. The blanks would have to be bigger than the planchets because they would be compressed in the upsetting mill. I'm not sure if the blanks would be larger than the coin they are eventually going to produce.

[MintErrors]

In my opinion, Blanks and planchets are the same thing.
Plachets start out a tad larger. Were talking very minute, 10/1000ths of an inch.
Planchets are then sent to the upset mill and turned into a type 2 planchet.
The planchet goes from slightly larger than a coin size to slightly smaller.
With the rim on the planchet it will be smaller than the diameter of the coin and fit in the striking chamber and collar.
When the hammer die struck the planchet into a coin, the coin is squeezed by tons of pressure. Sometimes near 50 tons.
The collar does a few things - keeps the coin round - and by squeezing the coin, it goes from being slightly smaller to legal coin size - and if the denomination requires the coin to be reeded, the collar has the reeding.
The reeding is added when the coin is squeezed and metal flows into the reeding area of the collar.

[kurtrr]

Got ya. Didn't realize the differences in sizes were so small. Definitely smaller that I can see or measure with what I have.
Thanks!

[MintErrors]

In my opinion, Arnold Margolis books are some of the best to learn from. He did the "Error Coin Encyclopedia". That book gives the basic tour of the U S Mint and describes what types of errors can occur in each phase.

Here is a dated video of the minting process.
Its for the multiple squeeze era which ended around 1996.

https://archive.org/details/ArnoldMargolis1990ANAb

[kurtrr]

Thanks, I am torrenting the video now.