Patterned Datums You can assign datums to hole patterns, concentric holes with gaps between them, width patterns, and concentric bosses. You can create datums as individual features or patterns using counterbores and countersinks. Four-hole pattern used as secondary datum Two concentric hole pattern used as secondary datum Five-hole radial pattern used as primary datum Two boss features used to define datum A Two width features used to define datum B Two counterbore holes used to define datum C Two countersink holes used to define datum B Parent topicDimXpert Related concepts 3D PMI Compare for DimXpert Annotations Is Enhanced Automatic Generation of DimXpert Annotations for Fastener Assemblies Customizable General Tolerances for DimXpert Displaying Component-level DimXpert Annotations in Assemblies General Profile Tolerance