TOLERANCE Command

Creates geometric tolerances

	Dimension toolbar:
	Dimension menu: Tolerance
	Command line: tolerance

The Symbol dialog box is displayed.

Geometric tolerances define the maximum allowable variations of form or profile, orientation, location, and runout from the exact geometry in a drawing. They specify the required accuracy for proper function and fit of the objects you draw in AutoCAD LT.

AutoCAD LT adds geometric tolerances to a drawing in feature control frames. These are frames divided into compartments that contain the geometric characteristic symbols followed by one or more tolerance values. Where applicable, the tolerance is preceded by the diameter symbol and followed by datums and symbols for their material conditions.

Symbol Dialog Box

Displays the geometric characteristic symbols for location, orientation, form, profile, and runout. Select the symbol you want to use. AutoCAD LT closes the dialog box and inserts the symbol into the Sym box in the Geometric Tolerance dialog box. The following table describes the symbols.

Symbol		Characteristic	Type
		Position	Location
		Concentricity or coaxiality	Location
		Symmetry	Location
		Parallelism	Orientation
		Perpendicularity	Orientation
		Angularity	Orientation
		Cylindricity	Form
		Flatness	Form
		Circularity or roundness	Form
		Straightness	Form
		Surface profile	Profile
		Line profile	Profile
		Circular runout	Runout
		Total runout	Runout

Geometric Tolerance Dialog Box

Specifies the symbols and values for a feature control frame.

Sym

Contains the geometric characteristic symbol you selected in the Symbol dialog box. Select a box to open the Symbol dialog box again.

Tolerance 1

Creates the first tolerance value in the feature control frame. Two modifying symbols can be included with this value: diameter and material condition. The tolerance value indicates the amount by which the geometric characteristic can deviate from a perfect form.

• Dia. Inserts a diameter symbol (Æ) in front of the tolerance value.
• Value. Creates the tolerance value. Enter a value in the box.
• MC. Displays the Material Condition dialog box, in which you select a symbol. These symbols act as modifiers to the geometric characteristic and the tolerance value of features that can vary in size.

Tolerance 2

Creates the second tolerance value in the feature control frame. Specify the second tolerance value in the same way as the first.

• Dia. Inserts a diameter symbol (Æ) in front of the tolerance value.
• Value. Creates the tolerance value. Enter a value in the box.
• MC. Displays the Material Condition dialog box, in which you select a symbol. These symbols act as modifiers to the geometric characteristic and the tolerance value of features that can vary in size.

Datum 1

Creates the primary datum reference in the feature control frame. The datum reference can consist of a value and a modifying symbol. A datum is a theoretically exact geometric reference used to establish the tolerance zone for a feature.

• Datum. Creates the datum reference value. Enter the value in the text box.
• MC. Displays the Material Condition dialog box, in which you select a modifying symbol. These symbols act as modifiers to the datum reference.

Datum 2

Creates the secondary datum reference in the feature control frame. Specify the secondary datum reference in the same way as the primary.

• Datum. Creates the datum reference value. Enter the value in the text box.
• MC. Displays the Material Condition dialog box, in which you select a modifying symbol. These symbols act as modifiers to the datum reference.

Datum 3

Creates the tertiary datum reference in the feature control frame. Create the tertiary datum reference in the same way as the primary datum reference.

• Datum. Creates the datum reference value. Enter the value in the text box.
• MC. Displays the Material Condition dialog box, in which you select a modifying symbol. These symbols act as modifiers to the datum reference.

Height

Creates a projected tolerance zone value in the feature control frame. A projected tolerance zone controls the height of the extended portion of a fixed perpendicular part and refines the tolerance to that specified by positional tolerances. Enter the value in the box.

Projected Tolerance Zone

Inserts a projected tolerance zone symbol,

, after the projected tolerance zone value.

Datum Identifier

Creates a datum-identifying symbol consisting of a reference letter preceded and followed by a dash. A datum is a theoretically exact geometric reference from which you can establish the location and tolerance zones of other features. A point, line, plane, cylinder, or other geometry can serve as a datum. Enter the letter in the box.

After you select geometric characteristic symbols and choose OK, the Geometric Tolerance dialog closes and, AutoCAD LT displays this prompt:

Enter tolerance location: Specify a location

AutoCAD LT places the feature control frame at the specified location.

Material Condition Dialog Box

Select the symbol you want to use. AutoCAD LT clears the Material Condition dialog box and inserts the symbol into the MC text box for the datum reference in the Geometric Tolerance dialog box.

Symbol		Term
		At maximum material condition
		At least material condition
		Regardless of feature size

Related Commands: DDIM controls dimension styles and settings such as lateral and limits tolerancing for dimensions. LEADER creates leader lines to which you can attach geometric tolerances
System Variables: DIMCLRE controls the color of the feature control frame. DIMCLRT controls the color of the tolerance text. DIMGAP controls the gap between the feature control frame and the text. DIMTXT controls the size of the tolerance text. DIMTXSTY controls the style of the tolerance text.