Flexural strength is the limit of a material to withstand flexural stress without failing. If an object is subjected to flexural stress, it will undergo both tension and compression behaviour because of bending moment. Flexural strength of a material will depend on either its tensile strength or compressive strength, whichever is lesser.
Most common example of a flexural stress is by bending an eraser into a U shape. The upper surface of the eraser will be subjected to compressive stress while bottom surface will undergo tensile stress. If you bend it further, you may see the bottom surface of the eraser will start to crack, which indicates that it the stress exerted to it is beyond its flexural strength.
