Looking for history of 5160 spring steel

[Chris Evans]

Originally Posted by Ian

The addition of chromium adds durability toughness to the steel, making it less likely to fail under a load.

Ian

Chromium in small quantities increases the hardenability of the steel and what this means in practical terms is that a low thermal shock oil quench suffices, reducing the chances of cracks and warping. Plain carbon steels of the 10xx type require much faster quenches, traditionally in water or brine.

The matter of toughness is more complicated and I refer you to the excellent articles on Larrin's website. This one is very recent: https://knifesteelnerds.com/2020/02/...-knife-steels/

Cheers
Chris