Parallelism tolerance specifies on of the following:
1. A zone defines be 2 planes or lines parallel to a datum plane or axis.
In this example, the surface of the feature must lie within 2 planes 0.25mm apart which are parallel to datum A.
|
Parallelism is the condition of a surface or axis equidistant at all points from a datum plane or axis. Parallelism tolerance specifies on of the following: 1. A zone defines be 2 planes or lines parallel to a datum plane or axis. In this example, the surface of the feature must lie within 2 planes 0.25mm apart which are parallel to datum A. |
|
|
2. A cylindrical tolerance zone whose axis is parallel to a datum axis. In the first example the axis of the hole must lie within a cylindrical zone of 0.3mm diameter parallel to datum A. In the second example this tolerance applies at the minimum diameter of 9.000 (MMC). As the feature size increases from MMC, the parallelism tolerance zone is increased a corresponding amount. The feature axis must also be within the specified tolerance of location. |
|