Custom coining is a factory key marking process that is used to enhance the security value of the key. Custom coining is different than key stamping. Stamping a key is good, but eventually that stamping can erode or become obscured due to wear. Keys that are merely stamped are also susceptible to alteration (removing or changing the stamping to something else, or simply removing the stamping all together).

Custom coining uses the same process that the US Treasury Department uses to mark coinage. During the coining process, about 10 tons of pressure is put on the key to embed a unique ID/marking (you chose the marking) on the key bow surface. The coining process leaves the key with a raised marking; similar to the raised markings you would find on a piece of US currency. The coining process also leaves the key with a jewelry style finish that signifies its high quality.

Language to use in key system specification:
The manufacturer will require the use of a specialized custom coining die (not stamped) to mark all of the blanks for the end user's system.