I wouldn't know, think they are cold formed from precision lead alloy wire I've only made them with the casting process with an LEM mould in the 80's which was very time consuming, take off your rose tinted specs mate & try some FTT's or jsb rs or express in your springers. We have a vast selection to choose from, ok you might need a mortgage to buy them now after brexsh*t but at least we still have the choice.....lol.