Made from two pieces of steel welded together, these knives are made the way the old fashioned knives were made.  One part, the backing, of a tough durable steel and the knife edge made from high speed Steel to hold the edge so necessary to the blades performance.  Not only are they some of the toughest knives for the price, they can be resharpened unlike the subsequent  planer models that use not so cheap  disposable blades.  The DW733 is probably the best value thickness planer and DW did it right.  I just wish they had take the good from the DW733 and improved upon it rather than making the replacement models they have come up with and are currently marketing.