GD&T Symmetry Definition

In GD&T, symmetry tolerance establishes a tolerance zone for the median points of non-cylindrical part features.  This tolerance is similar to concentricity, and the verification of symmetry tolerence is likewise time-consuming and difficult.  It is generally recommended that position, parallelism, or straightness be used in lieu of symmetry tolerance.

An example of symmetry tolerance is shown below.  The top figure shows the symmetry symbol applied to a notch.  The boxed symbols can be read "the median points of these opposing surfaces must be symmetric about datum axis A within a tolerance zone of 0.7".  The bottom figure shows and example part that meets this requirement.  The median points must lie between two planes 0.7 apart and equally spaced about datum axis A. 

Symmetry

Download CAD Software

Video Tutorial


"I am in awe at the usability and intuitive interface. Great work, I can't wait to build a few prototype fixtures. I was in need of a CAD program for a new netbook I recently purchased; was at home and needed to flesh out some ideas. One quick download, and in less than 15 minutes I had a good working diagram. The eMachineShop was perfect for my ..."
- Bruce H.
PCB CAD program

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

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

Mobile version

© 2015 eMachineShop.com | Admin | Site by Paradigm Site Ensemble CMS Copyright © 2015 Paradigm New Media, LLC. All rights reserved.