Boye Aluminum Crochet Hook Set, Sizes J-N Boye crochet hook set: sizes j,k,n (6mm-9mm) 3 Aluminum crochet hooks Each crochet hook 6-inch in length Boye crochet hooks feature optimally smooth throats and rounded heads for most precise, professional-looking work. Founded in 1906, Boye Needle Company was the first American manufacturer of crochet hooks and knitting needles.