The needle of system 328 has a left cutting point (135°) for working leather, synthetic leather and other coated materials – never for woven fabric, since the cutting action would sever the weave threads. It is used in industrial sewing machines for leather and synthetic-leather work, where the cutting point produces a clean puncture. Suitable machine classes are found, among others, at Dürkopp Adler (classes 069, 104, 105, 166), Singer (classes 45, 46, 47, 132) and Textima (classes 200, 211, 221, 223).
Thinner needle sizes are used, among others, for thinner to medium-weight leather, and the thicker versions for very thick, firm leather and multi-layer leather joins. As sewing thread, a bonded polyester or nylon thread such as Amann Saba or Coats Dabond is usually recommended, in a thickness matching the needle size chosen. A cutting point is required here to create clean puncture channels in firm materials.
