What is a projected tolerance zone?

What is a projected tolerance zone?

• A. A tolerance zone extended along a projection height to account for mating features that extend away from the part surface.
• B. A tolerance zone around the entire circumference.
• C. A tolerance zone used only for datums.
• D. A tolerance zone that applies to surface roughness.

Answer: (A)

A projected tolerance zone is a true-position tolerance zone that is extended beyond the surface of the part along a specified projection height. This models mating features that will protrude or extend away from the part surface after assembly, ensuring there is adequate clearance even when those features extend above the surface. The height of the projection is defined in the feature control frame and is used to account for how the mating feature will interact with the part in the assembled condition. This concept describes precisely a tolerance zone extended along a projection height to accommodate protruding mating features. It isn’t about a zone around the circumference, it isn’t limited to datums, and it isn’t related to surface roughness.

A projected tolerance zone is a true-position tolerance zone that is extended beyond the surface of the part along a specified projection height. This models mating features that will protrude or extend away from the part surface after assembly, ensuring there is adequate clearance even when those features extend above the surface. The height of the projection is defined in the feature control frame and is used to account for how the mating feature will interact with the part in the assembled condition. This concept describes precisely a tolerance zone extended along a projection height to accommodate protruding mating features. It isn’t about a zone around the circumference, it isn’t limited to datums, and it isn’t related to surface roughness.