NNP

Extrusion Dwell.  A pause in the press cycle with the die in the most extended position which allows the coin or medal being struck to stop the surface displacement (metal flow) that prevents its metal from springing back by molecular memory. The time for this is a fraction of a second, but since the piece is formed the instant of striking, the minute bit of time is sufficient.

excerpted with permission from

An Encyclopedia of Coin and Medal Technology

For Artists, Makers, Collectors and Curators

COMPILED AND WRITTEN BY D. WAYNE JOHNSON

Roger W. Burdette, Editor