In the textile industry, a hank is a coiled or wrapped unit of yarn or twine, as opposed to other materials like thread or rope, as well as other forms such as ball, cone, bobbin (cylinder-like structure) spool, etc.
[1] In yarns for handcrafts such as knitting or crochet, hanks are not a fixed length but are sold in units by weight, most commonly 50 grams (2 oz).
Special treatments to the materials that add cost, such as mercerisation or labor-intensive hand-painting of colors, can influence a manufacturer's desired length per unit as well.
Knitters and crocheters rewind the hanks into balls or centre-pull skeins prior to use, in order to prevent the yarn from becoming tangled.
[2] In the meat industry, a sheep, lamb or hog sausage casing is sold by the hank.