So the Brits, using Swedish steel, made from Swedish ore as early as the 1700 invent a new process where they remelt it in crucibles so there are no soft spots. This is "cast steel" This process probably set the steel world on fire and reflected the power of Britain.

In the mid 1800s blast furnaces do the same thing but better and by the ton, making cast steel much more expensive to produce.

Likely some of the razor makers in Britain held on to cast steel because of tradition and up comes the rest of the world razor makers with better steel, cheaper too.

Newer methods where carbon content can be varied. I think this is the main reason Sheffield steels are softer.

In that Jimmy mentioned about some of the Solingen razors with the sheffield steel was all about historic reputation.