until 1990 the mm was hand punched into the die. After that it was included on the hub. On a 1958 cent you could not have a doubled die with the same directional doubling on the mm and the date....it is machine doubling caused by chatter at the moment of strike.
Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.
Edited by amida17
04/03/2012 12:41 am