Nail_(unit)
Nail (unit)
Unit of cloth measurement
A nail, as a unit of cloth measurement, is generally a sixteenth of a yard or 21⁄4 inches (5.715 cm).[1] The nail was apparently named after the practice of hammering brass nails into the counter at shops where cloth was sold.[2][3][4] On the other hand, R D Connor, in The weights and measures of England (p 84) states that the nail was the 16th part of a Roman foot, i.e., digitus or finger, although he provides no reference to support this.[5] Zupko's A dictionary of weights and measures for the British Isles (p 256) states that the nail was originally the distance from the thumbnail to the joint at the base of the thumb, or alternately, from the end of the middle finger to the second joint.[6]
An archaic usage of the term nail is as a sixteenth of a (long) hundredweight for mass, or 1 clove of 7 pound avoirdupois (3.175 kg).[6]