87. Malaysia 20 Sen 1977 Rim-To-Rim Die Crack Error

image 1: obverse and reverse of the coin

  
    This is a major rim-to-rim die crack error coin, or can I use term multi rim-to-rim die crack error coin to this specimen? Interestingly the crack lines separate the reverse of the coin almost at the same area.

   For any mechanical engineering students out there, perhaps you are aware that failures are mostly happen at the area which has the stress concentration factors on it. So in attempt to analyse this specimen with my little knowledge, the crack initiation of the die might start along the tail of number "2", because it is located near the center of the  coin, which experienced the highest stress and pressure during striking stage. The crack grew along the tail to the rim at 8 o'clock and for some reason it splits into two crack lines, most probably to distribute the pressure and also to facilitate the other crack line that passed through the alphabet "Y" at 1 o'clock of the reverse.