1921 Peace Dollar

Quote:
The collar does not cut into the planchet, but the planchet seeps into the collar... A side effect of the planchet rim is that of lessened rate of displacement of the planchet metal into the collar crevices... This is because while the downward force of the upper die causes planchet displacement into the die devices of both dies (caused by the two fields closing), the planchet rim is not affected by this... it is forced horizontally into the collar as a secondary effect of the vertical momentum of the die closure, and the effect is lessened by the shape of the upset planchet edge.

The die rim (on each die) sits at a level on the die neck that is slightly below field level.... While die fields may clash, the a clash of the rims is physically impossible... they, (as the devices) are lower than the die field.

While the convex shape of the dies causes less striking pressure at the outer devices than the main ones, the rims are outside of the die field, so the planchet rims do not always even displace vertically to the die rims, because the planchet displacement that occurs outside of the die field is in a horizontal direction toward the collar... when the collar fills with metal, then additional metal is forced vertically toward the die rims.... depending upon the upsetting of the planchet, the rims may not completely fill.... but that is not really noticeable as the rim is already on the planchet.

I think that what is looked upon as extra metal on top of a coin rim is actually only the partial effect of complete metal displacement.

Neither planchets or die set ups were perfect, and a little wiggle room is necessary.