Talk:Turn per inch

The reciprocal of turns per inch...
The reciprocal of turns per inch must be inch per turn, not the inch. -- Perfecto 02:28, 13 November 2005 (UTC)
 * A turn is 2*Pi radians, and in the SI system, radians are unitless, so the units of tpi is inch-1, and the inverse of tpi is inches. Dgies 23:14, 6 September 2006 (UTC)