In GD&T, concentricity is a complex tolerance used to establish a tolerance zone for the median points of a cylindrical or spherical part feature. Concentricity is generally reserved for high-precision parts, and only when there is a need to control median points.

How do you use concentricity?

Unlike with coaxiality, you measure the circle of the plane. Put the stylus on the measurement point on the datum circle, and then put the stylus on the measurement point on the target circle to measure the concentricity. The stylus only comes into light contact with the surface and does not scratch the target.

What does concentricity mean in machining?

Description: Concentricity, sometimes called coaxially, is a tolerance that controls the central axis of the referenced feature, to a datum axis. ... Concentricity is a very complex feature because it relies on measurements from a derived axis as opposed to tangible surface or feature.