Shirogami 1 also referred as Shiro-Ko 1 or Shiro-Ko.
Identical to Aogami 1 (blue steel), except the absence of Cr and W.
So, it’s pretty much very pure carbon steel. Take very fine because of this.
Very popular knife steel for high end Japanese cutlery and especially with Honyaki type blades. Very good edge holding, gets very high hardness.