The stitch forming devise that carries the thread through the fabric so it can be interlocked with a bobbin thread. Sewing machine needles generally have nine basic parts including the butt, shank, shoulder, blade, groove, scarf or spot, eye, point, and tip. Needles are available with various points.  These include: Sharp points for piercing heavy, tightly woven fabrics; Ball pointed needles for sewing knits; and, A variety of specialty points for sewing leather and vinyl. Needles also come in many sizes. Two of the most common needle size systems are the metric size (i.e.,60, 70, 75, 80, 90); and the Singer numbering system (i.e.,9, 12, 14, 16).