Message:

<p>[QUOTE=&quot;Burton Strauss III, post: 4667144, member: 59677&quot;]You have to think about the physics of the striking chamber.</p><p><br /></p><p>The coin is held in position by a collar and during the instant of the strike the planchet (now coin) expands slightly to fill the collar.&nbsp; If the coin is struck without the collar it will expand larger than a normal coin.&nbsp; There is nothing normal that would make the rim go inwards like your 1974 shows - so PMD.</p><p><br /></p><p>The hammer die presses the planchet flat against the anvil die. Metal moves around and fills the voids in the die causing raised features on the coin. The flat part of the die presses and makes the field of the coin.</p><p><br /></p><p>And the proto rim from the upsetting machine expands to fill a tiny little gap between the die and the planchet. What could cause the cuts on your first coin? Nothing - it&#039;s a gap. So it&#039;s PMD.[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in