I originally posted the below paragraph on Yahoo Groups SRP.

From reading a lot of these posts and some other articles I have
come to the conclusion that the main difference between a good
straight razor and a bad straight razor is the different qualities in
the steel used for the blade.
Just exactly what are these different qualities? What brand
razors usually use good steel in their razors?

Maybe what I should have asked was what is the difference in hardness of different types of steel and other qualities of steel used in the blade of razors.
Bill