This International Standard specifies a method for the determination of the flat crush resistance of corrugated fibreboard used in the manufacture of shipping containers. This International Standard is applicable to single-faced and single-wall (double-faced) corrugated fibreboard. This International Standard is not applicable to double-wall (double-double-faced) corrugated fibreboard and to microflute corrugated fibreboard, since the end-point of the test is not clearly defined or observable.