A cooperative test program to evaluate testing procedures for the determination of J_Ic was organized under the auspices of ASTM. The material tested in this program was HY130 steel. A total of 21 laboratories in five different countries participated in this testing program. Although considerable scatter was found in the J_Ic results from various laboratories much of the scatter was attributed to material properties variations.

From the results of this program a recommended testing procedure was developed by a working group formed by the ASTM Task Group on Elastic-Plastic Fracture, E24.01.09. The data from the cooperative test program is presented along with the reasoning for developing the recommended J_Ic test procedure.