The needle of system UY 128 GAS has a medium ball point for working knit fabrics, without damaging the stitches. The KN version is a slim needle designed to protect fine knit loops from splitting, but without shank reinforcement and therefore more sensitive to deflection. It is used in industrial overlock, coverstitch and safety-stitch machines for elastic knit fabrics. Suitable machine classes are found, among others, at Kingtex (classes CT-4600-0-40M, CT-4603-0-40M, CT-4605-0-40M/RP, CT-4605-0-48M/RP), Kansai (classes BC-2000 C, BC-2000 PC, DLR-1502P, DLR-1502PMD) and Zoje (classes ZJ-2400A-140M-VF, ZJ-2400A-140M-VF-BD-D3, ZJ-2400A-148M-VF, ZJ-2400A-148M-VF-BD-D3).
Thinner needle sizes are used, among others, for fine, light jersey and tricot fabrics, and the thicker versions for heavy, dense knit fabrics and technical knits. As sewing thread, a matching thickness is usually recommended depending on the needle size chosen, e.g. from Amann Serafil or Rasant; for very stretchy seams, a texturised thread also works well. The ball point glides between the loops instead of piercing them, keeping the seam clean and undamaged.
