What keeps the coin from turning?

JD

US proof set coins are struck twice. That means the dies hit the planchet once, lift up or separate then hit it again. When this is happening what keeps the coin(s) in place such that the dies hit in the exact same spot? Why doesn't the coin spin from the strike?

Conder101

One, the proof presses run slower than the regular coining preses and the dies stay together for a moment before they open up again so there is no "bouncing" of the coin. Two, when the planchet is struck it spreads outward and is forced against the collar. This actually wedges the coin in fairly well and it takes some force to get it out of the collar. Three, on dimes, quarters, and halves when the plachet is forced against the collar it creates the reeding so the coin so it is like the coin is caught in the teeth of a gear. In order to turn it would have to rise up completely out of the collar. Then since it is exactly the same size as the inside of the collarit would almost certainly NOT drop back down inside. Four, after the first strike the coin is "contour" fit inside the anvil die.

TomB

Someone will correct me if I'm wrong, however, I believe the coins are held in place by a collar and they continuously sit on the reverse, or anvil, die. By being held in place on the anvil die they do not have the opportunity to rotate in between strikings from the obverse, or hammer, die.