Most cabinet scrapers are sheared from spring steel, hardened to Rc38-42. These scrapers are harder (Rc48-52) and hold an edge longer. The edges are carefully milled to a square, sharp 90° ready for immediate use on fine work. For heavy-duty use, a hook must be burnished onto them. The prepared edges not only save you the initial effort of filing and stoning, but indicate the condition they should be in the next time you intend to put a hook on them.