TS ISO 10578

TS ISO 10578 is a standard concerned with how a projected tolerance zone is defined and shown on a technical drawing within the broader field of orientation and location tolerancing. This concept matters when the allowable geometric variation must be considered not only at the feature’s nominal position, but also through a specified projection beyond the surface.

What a projected tolerance zone means

In general technical terms, a tolerance zone is the permissible geometric space within which a feature must lie. A projected tolerance zone extends that idea into a volume projected from the surface of the part, rather than limiting the control to the surface itself. This is especially useful where a feature such as a hole, pin, or similar functional element must maintain positional relationship across the depth of engagement in assembly.

What this standard covers

According to the scope, this standard defines the method of tolerancing by indication of a projected tolerance zone and specifies the method of indication on a technical drawing. In practice, that means its focus is the graphical and documentary expression of the tolerance, so that design, manufacture, and inspection can interpret the same drawing information consistently.

• Explains the indication method for a projected tolerance zone in technical drawings.
• Applies within the context of orientation and location tolerancing.
• Helps reduce ambiguity in geometric control documentation.
• Based on ISO 10578:1992; this TSE edition is withdrawn.

This type of tolerancing is particularly relevant where axis alignment, hole location, or the relationship of protruding features to mating parts affects assembly. The standard therefore supports clear drawing communication, so geometric tolerances are understood as an unambiguous drafting convention rather than as a vague dimensional note.