When making jewelry from wire especially in creating findings for closures and earwires you need to work harden the wire so it does not give when wearing. This is especially important on jumprings and your closures for as we all know your jewelry can get caught on anything pulling rings open or bending your closures opening it resulting in losing that very expensive and time consuming bracelet or necklace.
*A few steps I take are bending while working (normal designing benefit), hammering and also tumbling.
16 gauge copper wire created crimp hook and swirl closures which I recently made were design hardened, hammered and tumbled for strength.
Such simple steps to keep all of your hardwork safe and in place.