x17 SD1 is optimized for sewing dense fabrics, such as heavy sailcloth. These industrial needles also work for fine leather or leather clothing. Needle systems: x17, DPx17, , SY 10 per package. Features. Features a triangular cutting tip with a slightly rounded point; Use for leather, PCV. Groz-Beckert X16TRI Leather Sewing Needles Description: Pack of 10 Groz-Beckert® Leather Sewing Needles for Walking Foot Machines. Leather needle has the.