In the composites industry, a tow is an untwisted bundle of continuous filaments, and it refers to man-made fibres, particularly carbon fibres (also called graphite).
Tows are designated by the number of fibers they contain. For example, a 12K tow contains about 12,000 fibres.
In the textile industry, a tow (rhymes with cow, unless referring to cellulose acetate which sounds like toe) is a coarse, broken fibre such as flax, hemp, or jute. Flax tows are often used as upholstery stuffing, and tows in general are frequently cut up to produce staple fibre.
- ^ Glossary of Colonial Terms, History Online