: Identified by a number (e.g., IT7), this determines the magnitude (width) of the tolerance zone. Higher numbers indicate wider tolerances.
Understanding ISO 286 requires knowledge of three fundamental concepts: 1. Nominal Size The target dimension (e.g., ), which is the intended size shown on a technical drawing. 2. Tolerance Grades (IT Grades)
The shaft is always smaller than the hole, allowing for easy assembly and rotation.