Nylon Moisture Growth Calculator

Enter a nominal dimension and this returns how far it moves as the part equilibrates, against the tolerance band you were going to put on the drawing. The growth figures are the published ones for unfilled nylon 6 and nylon 6/6 — 1.5–2% equilibrium moisture in ordinary 35–65% RH air producing 0.5–0.6% growth, and roughly 0.1% for a highly filled grade, about 0.001 in per inch of dimension. They were published for moulded parts; the driver is the polymer rather than the forming process, so they carry across to machined stock, but the movement your part actually sees scales with its section thickness.