Abstract: An automated method and apparatus for grading pre-cut lumber products according to selected physical properties thereof such as modulus of elasticity (MOE) and modulus of rupture (MOR) are disclosed. A conveyor transports boards to be graded to an automated lumber feeding mechanism which sequentially rotates each board from a loading to a grading position. In the grading position, an impactor impacts one longitudinal end of the board to generate a compression force and a detector at the opposite longitudinal end converts the compression force to an electrical signal. Data acquisition circuitry samples and stores at least one cycle of the signal and a computer analyzes the samples and assigns values to predetermined parameters which characterize the signal. The computer utilizes the parameter values in one or more predetermined formulas which are optimum statistical predictors of the selected physical properties as a function of the parameters to obtain values for the selected physical parameters.