Datum plane意思

"Datum plane" is a term used in engineering and manufacturing, particularly in the context of metering and geometric dimensioning and tolerancing (GD&T). It refers to a theoretical plane that is used as a reference for locating and orienting features on a part, or for measuring geometric tolerances.

In GD&T, a datum is a point, line, or plane that serves as a reference for the location or orientation of a feature of a part. The datum is typically the feature of the part that is considered to be the most stable or the best basis for location or orientation.

A datum plane is one of three possible types of datums: a point (datum point), a line (datum axis), or a plane (datum plane). The datum plane is a flat surface that is used as a reference for the orientation or location of features on a part.

For example, if a part has a flat surface that is intended to be mounted against a surface, that flat surface might be designated as a datum plane. All other features on the part would then be located or oriented with respect to that datum plane.

Datum planes are typically denoted on engineering drawings and specifications, and are used as a basis for inspection and quality control. They are an important aspect of ensuring that parts are manufactured to the correct tolerances and specifications, and that they will fit together and function correctly when assembled.