I’ve made a few silver spanners over the years. The first one was in the early 1990s I think. They are cast in one or two cuttlefish bones depending on whether there is a flat side for engraving or not.
Casting always has some failures. In the case one half of the spanner wasn’t good enough, but there’s nothing wrong with the half you can see and I thought a key ring might be a good gift for a mechanic or engineer. You can buy this in my shop.