CPM S30V (commonly referred to as S30V) was introduced by Crucible in late 2001 / early 2002 in response to demand from the knife industry for a steel with more wear and corrosion resistance and more toughness. It has vanadium added for higher wear resistance and more molybdenum for better pitting resistance. It is also more resistant to edge chipping with superb edge retention. Contains about 1.45% Carbon, 14% Chromium, 2% Molybdenum and 4% Vanadium.
CPM-S35VN is a variation of CPM-S30V with slightly altered elements to improve its toughness. The Vanadium is lowered by 1%, and 0.5% of Niobium is added. This change makes CPM-S35VN about 15-20% tougher than CPM-S30V without any loss of wear resistance. It is also easier to machine and polish can CPM-S30V. It is resistant to edge chipping with superb edge retention. Contains about 1.40% Carbon (C), 14% Chromium (Cr), 2% Molybdenum (Mo), and 3% Vanadium (V), and 0.50% Niobium (Nb).
CPM-S45VN is one of the newest steels on the block (New for fall of 2019), but is already becoming popular with knifemakers. Chris Reeve, Buck Knives, Spartan Blades, and Spyderco all already have blades made with CPM-S45VN. It is a variation of CPM-S35VN but with rebalanced chemistry. It adds additional chromium to form more chromium carbides and leave some more free Chromium (free Chromium is necessary for rust resistance). CPM-S45VN offers slightly improved wear resistance over CPM-S35VN. It has similar toughness (slightly below S35VN and slightly above S30V), but it has significantly better Corrosion Resistance than either.
Contains about 1.48% Carbon (C), 16% Chromium (Cr), 2% Molybdenum (Mo), 3% Vanadium (V), and 0.50% Niobium (Nb), and 0.15% Nitrogen (N).
CPM, or Crucible Particle Metallurgy uses Power Metallurgy in the creation of steel. Each of the metals in the steel melted down in their own homogenous molten bath, then spurted out in a powderized form. These smaller particles, or powder, is then used with the other elements to make the desired steel. This allows for rapid solidifcation of the steel which reduces elemental segregation (so Chromium has less time to seek out other Chromium particles), which gives the steel a much more consistent, predictable, and smaller microstructure. This consistency improves the machinability, grindability, toughness, and wear resistance (part of edge retention).