The B-63 BLUK needle (needle system B-63) has a normal round point for working woven and knit fabrics. It is used in industrial overlock, coverstitch and safety-stitch machines. Suitable machine classes are found, among others, at Dürkopp Adler (classes 721, 932, 933, 934), Rimoldi (classes F 61, F 63, F 64-00-1MA, F 64-00-1MD) and Willcox (classes 900, 928, 950, 951 -).
Thinner needle sizes are used, among others, for light, fine woven and knit fabrics such as blouse and shirt fabrics, and the thicker versions for heavy, multi-layer woven and knit fabrics as well as technical textiles. As sewing thread, a matching thickness is usually recommended depending on the needle size chosen, e.g. from Amann Serafil (polyester) or Rasant (polyester/cotton).
This version has a BLUKOLD coating: a roughened, phosphated surface with a subsequent Teflon coating, on which melt residue settles much later than on chrome-plated needles. It is especially suited to synthetic materials and materials with a high synthetic-fibre content.