While not a powder steel (a method of making steel using ultra pure, micro grains of steel that are heated and pressed together), 154CM is widely used in nicer knives. It is a good balance between all three attributes, being relatively hard, tough and corrosion resistant. It is very similar chemically to RWL 34 and ATS-34. If the knife you are looking at has a 154CM blade, you’re fine. Note: There is a powder metal version called CPM154 that is purer than the non-powder version, making it easier for knife makers to grind. CPM154 is a truly superior steel.