Might have something to do with metal compatability to vending machines...ever try to use a slug in a coke machine?
good balance between technology & price Copper-Nickel alloys had proven long term performance. It was a multi-faceted study of weight, density, electrical characteristics, magnetic characteristics, anti-counterfeiting characteristics, vending machine compatibility, manufacturability, cost of manufacture, Olin's lobbying, etc. Clad Copper Nickel apparently provided a good balance between all these things. I don't have my books with me but isn't it something like 90-10 on the inside and 10-90 on the outside? Very best regards, collect89
The government primarily was lokking for a material that wouldn't attract much attention so it had to look a lot like silver. The cu/ ni clad cu composition was first mentioned by a representative of the vending industry which said this sort of material would be the most difficult to distinguish from silver so was the biggest threat to the industry. The mint started playing around with all sorts of sandwich metals looking for one which would appear to be silver and work with the silver already circulating while being cost effective. The 25% Ni 75% Cu cladded pure copper is rather expensive but was the cheapest which did the job. In those early day they couldn't bond these metals with pressure from rollers because there was no steel strong enough. To bond them they had to have all four surfaces perfectly clean and then they were forced together in a hydraulic press and dynamite was detonated above them. By 1968 some of the clad strip could be made by rollers and it was only a little later that it was all made this way.
Back in the 1960s, people still held the antiquated opinion that money should have intrinsic value. Paper unbacked by anything and slugs didn't pass well for money. Now most people actually believe that wealth comes out of a printing press and that there is an unlimited supply of it burried somewhere under the US Capitol. Money could be made from recycled plastic soda bottles and people wouldn't know the difference. Interesting, gold, silver and copper have been the three metals most used as money throughout history, and all three appear in the same column of the periodic table of elements. So people somehow instinctively settled on these three metals long before anyone even knew they were elements.
With the reserve banking requirements in place in 1964 the currency was hardly backed by metal. The coins may have been silver (except cent and nickel) but the paper was backed mostly by the full faith and credit of the US government just as it is today.
This is the line they give us today, and today it is pretty much true, but that wasn't the case in 1964/65. Back then the electrical and magnetic properties weren't that important because the coin detection mechanisms in the vending machines were strictly mechanical and didn't measure electrical or magnetic properties (Other than a magnet to make sure it wasn't a steel slug) They only checked weight, diameter, thickness, and for a hole in the center to make sure it wasn't a washer. Besides Coppernickel clad and 90% silver do not have the same weight , density, electrical or mechanical properties, and they were not very compatible in the vending machines mainly because of the difference in weight. A machine adjusted for silver tended to reject the clad coins, and one set for the clad would reject the silver ones. And if the tolerances were set so broad so as to accept both, they tended to accept anything. (Todays vending machines will also usually reject silver coins because they don't have the electromagnetic signature of the clad coins that todays machines check for.) This was probably the major reason for the choice, the material was and still is, very difficult to produce and therefore counterfeits would also be very difficult to make.
