Dimensional change caused by heating.

Position change caused by temperature variation.

Bending or displacement under load.

Deviation from ideal rotational or linear movement.

Accuracy of linear Z-axis travel.

Accuracy of right-angle relationships involving Z.

Correct positioning of Z-axis components.

Accuracy of a Z-axis relative to another axis.

Degree to which Z-axis surfaces remain parallel.

Structural resistance to unwanted movement.