That springy Copper is probably Beryllium Copper.
https://en.m.wikipedia.org/wiki/Beryllium_copper
My Tech teachers when i did my Apprenticeship told me that in their time one guy had a polished up Beryllium Copper Cresent ( adjustable spanner/wrench ) wrapped up in cloth in the back of his toolbox.
The joke was that the new Apprentice would get asked at some point to go around & find out "Who's got the Golden spanner ".
He would go around thinking that this is a joke untill somebody actually does pull one out of their toolbox & very carefully presents it to them on a clean cloth background.
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