ISO 13821:2002

This International Standard specifies a method for the determination of the edgewise crush resistance of corrugated fibreboard. The force is applied in the direction of the flute axis.
This method is applicable to single-wall (double-faced), double-wall, and triple-wall corrugated fibreboard. It may also be used to test samples taken from corrugated cases and other converted products.
While the method is applicable to waxed corrugated fibreboard, care must be taken that the heat used in the waxing step does not affect the corrugated structure. This is controlled by observing that failure during the test still occurs away from the loaded edges.