This part of ISO 13935 specifies methods for the determination of seam maximum force of sewn seams when the force is applied perpendicularly to the seam. This part of ISO 13935 describes the method known as the grab test.NOTE ISO 13935-1 describes the method known as the strip test. For informative references see the Bibliography.The method is mainly applicable to woven textile fabrics, including fabrics which exhibit stretch characteristics imparted by the presence of an elastomeric fibre, mechanical or chemical treatment. It may be applicable to fabrics produced by other techniques. It is normally not applicable to geotextiles, nonwovens, coated fabrics, textile-glass woven fabrics and fabrics made from carbon fibres or polyolefin tape yarns (see Bibliography).The sewn fabrics may be obtained from previously sewn articles or may be prepared from fabric samples, as agreed by the parties interested in the results.This method is applicable to straight seams only and not to curved seams.The method is restricted to the use of constant rate of extension (CRE) testing machines.