Not sure about the 1983 50 cent, but the other two are PMD.
The irregular shape of a 50 cent coin causes them to occasionally get stuck in various types of coin machines where the teeth of a metal cog create an impression on one of the 12 corners.
The irregular shape of a 50 cent coin causes them to occasionally get stuck in various types of coin machines where the teeth of a metal cog create an impression on one of the 12 corners.























