John in NM
Plastic failure is what he described - and a knife is just as useless bent as broken. Depending on the application, both are often characterized as failure. In some applications a bending failure is more desirable, yet still a failure.

To my thinking, the test described is pretty pointless. A more interesting test would demonstrate that some blades can behave elastically under the conditions which either bend or break other blades.

Bending or breaking blades with no measurement of the forces applied and the point when deformation changes is a pretty dull test if one wants to actually find the better steel.