GD&T Runout Definition

In GD&T, runout tolerance is used to control the location of a circular part feature relative to its axis.  This is different than circularity, which controls overall roundness.  Runout is usually applied to parts with circular cross sections that must be assembled like drill bits, segmented shafts, or machine tool components.  Runout helps to limit the axis offset of two parts to ensure they can spin and wear evenly.

An example of runout tolerance is shown below.  In the top figure the runout symbol is applied to the angled surface.   The boxed symbols can be read "each circular element of this surface must have full indicator movement (FIM) of less than 0.1 relative to datum A".  The bottom figure shows a sample measurement taken at one cross section, but multiple measurements are required to verify runout.  Note that the indicator is applied perpendicular to the measured surface, and that this tolerance controls only individual circular elements and not the whole surface simultaneously (see total runout).

runout2

Download CAD Software

Video Tutorial


"Thank you. I hoped that there was this kind of service on the net and there you are. And it wasn`t hard to find you. The term "sheet metal online order part" did the trick."
- Julius
PCB CAD program

Design printed circuit boards online at our PCB division - Pad2Pad.com

Design services
Visa Mastercard Amex Discover
eMachineShop.com | 31 Industrial Ave. | Mahwah, NJ 07430 | Phone 201-962-7511 | Questions? Contact us.

© 2014 eMachineShop.com | Admin | Site by Paradigm Site Ensemble CMS Copyright © 2014 Paradigm New Media, LLC. All rights reserved.