school me on struck from proof dies

lasvegasteddy · February 22, 2012 11:53PM

why do i see some coins noted as struck from proof dies but are not proof coins?

isn't the dies used truly is what determines what the coin is?

guitarwes · February 22, 2012 11:57PM

Some Proof dies were used to strike business strike coins, either by mistake or on purpose. Case in point is the Type B Washington Quarter whose reverse die started life as a Proof die.

lasvegasteddy · February 23, 2012 12:02AM

so by all rights aren't they...proof reverse business obverse like the 2008 eagles???

ModCrewman · February 23, 2012 12:03AM

"Proof" is an entire coin making process, including preparation of the dies, and method of striking. Dies may be prepared for striking of proof coins (polished, detailed, etc.) but not struck using the proof striking methods, which historically have meant, slower higher pressure striking, or even "struck twice". Proof dies are also refurbished more frequently to maintain the level of detail and strike quality. Historically a die that has initially been prepared to strike a proof coin may have been called into use in the high speed, high volume striking of a business strike coin after being retired as a proof die; although I do not anticipate that this has regularly been the case since probably the 1950's at the latest.

mingot · February 23, 2012 12:12AM

Don't forget the planchet preparations, which also won't happen during business strikings.

19Lyds · February 23, 2012 12:39AM

<< so by all rights aren't they...proof reverse business obverse like the 2008 eagles??? >>

No. The proof reverse for 2008 had the same "design" as the Burnished Uncirculated coin. However, that design was changed in 2008 from what is was in 2007. (i.e. serifed U )

Proof Designs and Business Strike Designs are not always the same. Prime examples are the Washington for 1937-1972), Lincoln Cent, and Eisenhower Dollars. Of the three, some years had incidents where the die intended for the proof version ended up in the business strike presses.

The exact reasons are speculative in either a cost savings nature or an "Oops" nature.

derryb · February 23, 2012 1:00AM

The final product determines if proof or not. Proof dies are normally highly polished to result in mirrored fields. The 1999 W unc. $5 and $10 are good examples of using unpolished proof dies to strike business coins. In this case the presence of the W on the dies made them proof dies except they didn't get polished. The result was business strike coins with a mintmark that is normally reserved for AGE proofs.

19Lyds · February 23, 2012 1:08AM

<< The final product determines if proof or not. Proof dies are normally highly polished to result in mirrored fields. The 1999 W unc. $5 and $10 are good examples of using unpolished proof dies to strike business coins. In this case the presence of the W on the dies made them proof dies except they didn't get polished. The result was business strike coins with a mintmark that is normally reserved for AGE proofs. >>

Actually, proof dies are only "highly polished" further into the production process. They begin life the same way as a business strike die except fir, in some case, with a different design.

I think that if folks leave the "polished" aspect out of it and concentrate on the design then it becomes easier to understand the collectibility of the business strike coin with a proof reverse design or in some cases, the proof coin with the business strike reverse design.

It's the design which is different, not the manufacturing process the die goes through.

derryb · February 23, 2012 1:13AM

<< It's the design which is different, not the manufacturing process the die goes through. >>

Not always the case such as with the 1999 W unc. $5 and $10 AGEs. Only difference in design between proof and business strike coins is the addition of the mintmark for the proof.

19Lyds · February 23, 2012 1:16AM

<< 

<< It's the design which is different, not the manufacturing process the die goes through. >>

Not always the case such as with the 1999 W unc. $5 and $10 AGEs. Only difference in design between proof and business strike coins is the addition of the mintmark for the proof. >>

Am I not correct is saying that the mintmark is part of the design since it was not added after the die was produced?

Or were mintmarks still being hand punched in 1999?

cladking · February 23, 2012 1:46AM

Another part of proof die production is that among the final steps the die is often basined where the fields
(high part of the die) are ground flat or with a slight convexity. This is sometimes done with regular dies as
well though usually not so evenly as with proof dies. Proof dies can be used on circulation issues without
this final step.

Normally the only thing of interest to the collector is what accounts for the unusual appearance of a given
coin and this does often involve the preparation of the dies used to make it but it also can involve the plan-
chet on which it was struck since these can acquire degrees of polishing or vary from one to the next in
hardness, temperature, size, etc.... There are large numbers of processes and conditions that can affect
the final products and identifying them tends to be largely dependent on experience. Sometimes it's very
easy and sometimes it's not.

SMS's ('65 to '67) can teach one a great deal about these differences because there are numerous different
techniques that were used to make them. The coins vary from virtually identical to circulation issues to what
are probably true proofs and most were struck with fully proof dies. It's difficult to use knowledge gained in
one series and transfer to another but once you can see a specific difference you'll probably be able to see it
almost anywhere.

school me on struck from proof dies

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