Which tolerances govern how far a feature's centerline or surface is from a datum reference?

Which tolerances govern how far a feature's centerline or surface is from a datum reference?

• A. Form tolerances
• B. Orientation tolerances
• C. Location tolerances
• D. Runout tolerances

Answer: (C)

In GD&T, the tolerance that governs how far a feature’s centerline or surface can deviate from datum references is the location tolerance. This type of tolerance defines a zone where the true position of the feature must lie relative to the datums, effectively controlling the feature’s distance from those reference frames. For a hole, that zone is often a cylindrical region around the true position, ensuring the hole’s center stays within a specific distance from the datum references. This is different from form tolerances, which only constrain the shape (like straightness or flatness); orientation tolerances, which control angular relationships; and runout tolerances, which measure variation as the part rotates. So, when you need to specify how far the feature’s center or surface can be from datum references, location tolerances are the one that does that.

In GD&T, the tolerance that governs how far a feature’s centerline or surface can deviate from datum references is the location tolerance. This type of tolerance defines a zone where the true position of the feature must lie relative to the datums, effectively controlling the feature’s distance from those reference frames. For a hole, that zone is often a cylindrical region around the true position, ensuring the hole’s center stays within a specific distance from the datum references. This is different from form tolerances, which only constrain the shape (like straightness or flatness); orientation tolerances, which control angular relationships; and runout tolerances, which measure variation as the part rotates. So, when you need to specify how far the feature’s center or surface can be from datum references, location tolerances are the one that does that.