Convert from stick to shaftment

Unit Definition (stick)
A stick, when used as a unit, is usually two inches, i.e. 5.08 cm (for the international inch). It was once used in the English tailoring business, but has since fallen out of use completely.

Unit Definition (shaftment)
A shaftment, when used as a unit of length, is usually six inches or two palms, i.e. 15.24 cm (for the international inch). It is thought to be the distance from the tip of the outstretched thumb to the other side of the palm.In English this unit has mostly fallen out of use, as do others based on the human arm: digit (1/8 shaftment), finger (7/48 shaftment), palm (½ shaftment) hand (2/3 shaftment), span (1½ shaftments), cubit (3 shaftments) and ell (7½ shaftments).