Edge StabilityRoman argues that we need to have a test that shows which steels and heat treatments lead to the best behavior when it comes to supporting a thin, very acute edge. With thin, low angle edges the possibility of edge rolling and/or chipping is much stronger than the possibility of edge wear. Therefore we must have an understanding of what leads to edge rolling and chipping to know how to best support the thin, low angle edge. This resistance to rolling and chipping is what Roman has defined as “edge stability.”Hardness and Yield StressFirst is the potential for edge rolling. If a small stress is applied to an edge and then removed the edge will return to the original position. However, if the stress applied to the edge exceeds the yield stress of the material, then the edge will be permanently deformed, or rolled. Higher hardness usually means higher yield stress [5]: