Spring Dividers, 6 in

Description

Brass-and-steel spring dividers for stepping out sewing stations, marking board margins and transferring a measurement without reading it off a rule. A bow spring holds the legs under constant tension and a knurled adjusting nut sets the span, so a distance can be carried across a run of sections without drift — which is the whole point, because a station set from a rule twenty times is twenty chances to be a millimetre out. The points are hardened and can be re-dressed on a stone. In a bindery this is less a measuring tool than a repeating one: set it once from the first section, then walk it down the rest. Also the fastest way to divide a spine into equal parts by trial, which is how it was done long before anyone typed a number into anything.