A wood property that is indicative of high flexure is one called toughness, defined as the “energy required to cause rapid complete failure in a centrally loaded bending specimen.” This differs from MOR, which involves a gradual load increase. Woods that can absorb considerable energy by bending before failing when an impact load is applied will be tougher. The machine designed for testing toughness uses a weighted pendulum arm that is released to break the test beam. The original angle is compared to the final angle of the pendulum to determine the energy absorbed in fracturing the beam.