Someone teach me the precise difference between Open and Closed Collar minting
STONE
Posts: 15,275 ✭
I need a crash course (Minting-101) on the differences between these two coin manufacturing methods.
I believe I have a decent handle on the difference between the two, but I need some reassurance.
Thanks for any and all help
I believe I have a decent handle on the difference between the two, but I need some reassurance.
Thanks for any and all help
0
Comments
An open collar is a metal plate with a circular hole cut in it. The hole is small enough to keep a planchet in the correct position for striking, but not so small that the collar affects the edge of the planchet. This is especially important where the planchet edge has been lettered or ornamented before striking. Coins made with an open collar differ slightly in thickness and diameter from one another.
Closed collar –
A closed collar is a metal plate that has a circular hole of a specific diameter for each denomination as stipulated by law. Planchets are made slightly smaller than the collar, and when struck, the planchet metal is pushed into the face designs as well as against the collar (or “edge die”). This imparts the edge design (usually vertical reeding) and also forms the protective rim in conjunction with the face dies. A closed collar also ensures uniformity in diameter and contributes to consistent thickness.
Does this help?
An open collar is a metal plate with a circular hole cut in it. The hole is small enough to keep a planchet in the correct position for striking, but not so small that the collar affects the edge of the planchet. This is especially important where the planchet edge has been lettered or ornamented before striking. Coins made with an open collar differ slightly in thickness and diameter from one another.
Close RWB (no pun intended), but not exactly correct for all denominations.
I have an article that is almost completed and will be published in the JR Journal that has some added information about this subject. Stay tuned...
QN
Go to Early United States Coins - to order the New "Early United States Half Dollar Vol. 1 / 1794-1807" book or the 1st new Bust Quarter book!
What I wasn't as certain about was the difference in size between the "circular hole in the metal plate"
Now - for the super secret REAL meaning:
Open collar - press operators could open the top button on their shirts and also roll up their shirt sleeves to the elbow. Only in hot weather. Female press operators could do none of these things.
Closed collar - shirts had to be buttoned to the top and sleeves buttoned at the wrists. Celluloid collars were worn if the boss was on the floor.
How would the Open and Closed Collar methods affect the dies striking the coins?
<< <i>Another question:
How would the Open and Closed Collar methods affect the dies striking the coins? >>
In theory the collar dies should never come into complete contact with the dies. The dies diameter should fit just inside the diameter of the collar die. There would be a slight increase in pressure directed upward and downward into the dies from the planchet being contained by the close collar die, however it would be a very miniscule amount. Other than that, it should work the same as with the open collar.
Hope this helps!
QN
Go to Early United States Coins - to order the New "Early United States Half Dollar Vol. 1 / 1794-1807" book or the 1st new Bust Quarter book!