The UY 501 GS needle has an extra-narrow spade point 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 Union Special (classes 2600, 9500 G, 9900, 14700 D), Mauser (classes BIH, DDE, F, F -SP 23200- -2,5) and Pfaff (classes 2028, 2053, 2028 - 1-4-19, 2053 - 1-2).
Thinner needle sizes are used, among others, for thinner to medium-weight leather, and the thicker versions for medium-weight leather for everyday leather goods and saddlery work. As sewing thread, a bonded polyester or nylon thread such as Amann Serabond, Amann Strongbond 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.