Abstract: An apparatus for determining the presence or absence of a predetermined minimum flexural strength and stiffness of a relatively rigid material, said apparatus comprising:a frame, a pair of flexure means, each flexure means affixed on opposite sides and ends of a support means affixed to said frame, and equidistant from a fulcrum means for said support, said fulcrum means affixed to said frame with a pivot point at the midpoint thickness of the material to be tested, a pair of guide means, each guide means affixed to said frame equidistant from said fulcrum means and positioned on opposite sides of and apart from said flexure means whereby the material to be tested is guided between the flexure means and guide means in a substantially horizontal path, a load means affixed to said frame for applying a predetermined force to said support means whereby the flexure means deflects the relatively rigid material, and sensor means affixed to said frame for detecting the amount of deflection of said material.