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Perpendicularity constrains how square a face or an axis is to its datums. In ASME Y14.5 it is an orientation tolerance: the surface must lie in a zone that is exactly 90 degrees from the primary datum. It does not locate the feature. A face can be perfectly square to datum A and still sit in the wrong place; that location is Position or a Direct Dimension. Perpendicularity is in the Toolbar in Dimensioning Mode.

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Which features it accepts

  • A plane — a face that should be square to the datum.
  • A cylinder — a hole or a pin whose axis should be square to the datum.
The primary datum can be a plane, a midplane, or an axis. A secondary datum is allowed only when it clocks the zone: a plane feature whose primary is a plane or a midplane. In that case the secondary is itself a plane datum, and it is optional. A tertiary datum is not used. Every other combination refuses the extra datum rather than ignoring it.

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The tolerance zone

The default zone is the space between two parallel planes, set square to the primary datum. The tolerance is the distance between those planes, in millimeters. Diametral zone (⌀) is available for a cylinder whose primary datum is a plane or a midplane. The zone is then a cylinder around the true axis, and the tolerance is a diameter. A cylinder held the other way — across the datum rather than along it — stays a two-plane zone, and the diametral toggle is not offered.

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Workflow

1

Select Perpendicularity

Choose Perpendicularity from the Toolbar, or right-click a plane or cylinder and choose Add perpendicularity control….
2

Pick the feature

Click the face or the cylinder to control. Eligible features highlight on hover.
3

Set the tolerance

Enter the tolerance. Turn on Diametral zone (⌀) when the control is a cylinder square to a plane datum and the drawing uses a diameter.
4

Select the datums

Pick the primary datum. Add a secondary plane datum only when the panel offers that rank.
5

Place the callout and submit

The callout section opens once a feature is picked. Submit to add the control to the feature set. Drag the leader to place the label.

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Reading the result

The callout reports how far the feature leans out of the square zone, and whether that is inside the tolerance. Measured in names the datums. Open freedoms lists motion the datums did not stop. Edit the tolerance afterward; the pass or fail state updates without a new extraction.