KikuichiMolybdenum Pro Series consist of high molybdenum content steel, often referred to as "moly steel". This formulation provides a great edge that is easy to resharpen and is less expensive than some other alloys. This steel type was popularized by Mac Knives, and highly regarded for the extreme razor edges that it produces. The absence of vanadium makes the knife less resistant to harsh chemicals which could cause some discoloration. So please keep these knives away from full-strength bleach and degreasers, (which you wouldn't want on any knife).