What the hell is HCS-1718 steel?

[y53p]

I’m about to get my hands on a John Ek commando 5 (https://www.arizonacustomknives.com/products/1053059/), made in the 90s. I’ve found vague references to the steel used and one particular reference being thrown about it in an old thread saying it’s made out of HCS-1718. Any idea on what steel this is or if it’s any good?

 

[TheEdge01]

Here’s an old thread that may shed some light on the subject.

 

[justjed]

As far as I know, 90s Eks were made from 440C. But, it was also a thing, among some manufacturers, to use a specific heat-treat protocol, and give the result a new name. Thus, 440A, with heat-treatment X, became QS-13...

 

[greater]

Another marketing spin for 440C steel which was probably considered one of the better steels of the time? It sounds like a money making scheme.