Groz-Beckert #18 Leather Sewing Machine Needles 135x16 Triangular Point (10 pack) are industrial leather needles that feature a round shank and a three-sided cutting point. These specialty leather needles make clean, triangular cuts in leather. This results in a straight seam with slightly elevated stitches. For best results, use a triangular needle to sew medium or long stitches in thick leather. As an added bonus, all Groz-Beckert needles are free of burrs. Burrs can make it difficult to insert the needle into a sewing machine, as well as cause thread separation and skipped stitches. Once you start sewing leather with high-quality Groz-Beckert triangular needles, you'll wonder how you ever did without them.