Material characterization studies using the multi-specimen J resistance curve procedure have been carried out for a variety of alloy steels. These results along with the data from the literature have been used to demonstrate that the J resistance curves can be normalized to a single R curve. It is shown that J-controlled crack growth is reasonably unvarying with the size of the specimen provided the minimum size requirements to insure a J-based dominance of the crack tip region are satisfied. A relatively simple procedure is proposed to permit an assessment of a critical value of the J integral, the slope of the J integral resistance curve, and the tearing modulus from a single specimen.