Ordinate dimensioning is used when the X and the Y coordinates, from one location, are the only dimensions necessary. Usually the part has a uniform thickness, such as a flat plate with holes drilled into it. The dimensions to each feature, such as a hole, originate from one datum location.

Do ordinate dimensions require dimension lines?

Ordinate dimensions appearance is also different. Each dimension has only one leader line and a numerical value. Ordinate dimensions do not have extension lines or arrows.

Can ordinate dimensions be basic?

We have a pattern of holes which are located using ordinate dimensions. Their tolerance zones are specified using a position tolerance frame, so the dimensions themselves are basic.