The UY 121 GHS needle (needle system MY 1001) has a medium ball point for working knit fabrics, without damaging the loops. It is used in industrial chainstitch and general-purpose sewing machines for everyday garment and textile manufacturing. Suitable machine classes are found, among others, at Union Special (classes 3000, 9500 D, 10600 L, 11500 A, K), Mauser (classes AA, ABG, AE, AHF) and Singer (classes 62, 106, 109, 147).
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.
