Die Retention. Setting aside dies that are later used for restriking that was not originally intended. This term applies more for coin dies than medal dies which are typically stored for later striking, as for an award program. Storing dies must be done in very controlled conditions and location. The striking surface must not be exposed to moisture, causing, of course, rusting on the surface. Even air can be a source for deterioration. Dies do tend to become brittle over time, so a complete understanding of iron metallurgy, hardness, heat treating, setup and testing for the restriking of these pieces. See die vault, rusted dies, restrike.

References:

NC10 {1962} Newman and Bressett, p 84-86.

Illus: Drawing, Photos Douglas 7,8