It seems to me that with the planchet change for the 1943 cent...strike issues would have been common. Especially since they went to a steel planchet which should be harder than the previously used copper planchet. Did the 1943 cents have strike problems? From what I have seen, well struck examples aren't that hard to find but intuitively I would think they would be rare. The reason I ask is I have always loved the '43 cent and would love a set of MS66 coins...but I want to understand the strike quality and be able tp better select the coins prior to purchase.
Most '43 Cents are surprisingly well-struck. This is a conundrum that I too have wondered about. It seems like striking steel planchets would take a lot more pressure and also cause a lot more die wear, and since it was being done in wartime I'd also expect a bit more "shoddiness" to be allowed, meaning that dies would be pushed longer with more wear allowed, etc. But most of the '43's I've seen have few issues other than the well-known die polishing issues. Hopefully someone else has further insight into this as I would love to hear from an authoritative source why this is the case.
To quote Lange; "1943-P cents are usually well struck, and many survive with their brilliant, pristine surfaces in tact. ........... The steel used for this issue was know to be harder than the bronze and brass alloys used previously, so the mints were required to reduce the set distance between the dies when coining cents." As for die wear, the dies do not contact the harder steel. They do contact the zinc and zinc is softer than bronze/brass. This is my opinion, not from Lange.
If the planchets were harder one would think they'd be less-impressionable. Why, then, reduce the space between the dies, in effect, reducing the striking-pressure? That doesn't seem to make sense when one is trying to impress a harder planchet. One would think in a case like that one would want to employ a method to increase the striking-pressure rather than reduce it.
Steel is not "less-impressionable". It merely takes more force (pressure) to impress it. The force exerted by the die is inversely proportional to the distance between the dies. i.e. the smaller the gap, the greater the force or pressure.
But my understanding (and I could be very wrong) is the zinc coating was pretty thin. Therefore...the steel underneath would be affected by the striking as well. I was thinking it would be like punching a brick with a thin layer of foam around it...it is still pretty hard.
Die wear comes from friction. Just like oil reduces friction on moving parts, the zinc reduces the friction to the dies. It makes not difference how thick it is so long as it covers the surface.
That makes sense. I wasn't really thinking about die wear though. I was thinking about striking a hard surface and having mushy details as a result. The same reason early Ike Dollars are poorly struck...not because of worn dies but because of hard planchets.
Can someone nominate this thread as a keeper. What a wonderful dialogue to follow on such an interesting topic. I have a metal stamping/production background. This is really cool. I was trying to guess the answer and do some mental exercising as I read. Very nice.
43's are usually very well stuck. The only weakness I notice is sometimes on the reverse wheat stalk lines but some of that maybe due to die wear.
However, relatively speaking, a coin press would be like concrete on plastic covered with Styrofoam. The yield strength for tool steel is 5000 KPA, for steel 200 KPA, copper 130 KPA and zinc 100 KPA. Tool steel is so much harder than any coin material, it would be off the scale. BTW, you Ikes have another problem. Pressure is force per unit area. The Ikes have 4 times the area of a Lincoln and thus start off at needing 4 times the pressure.
