A lateral tolerance specifies the amount by which a dimension can vary. By specifying tolerances in manufacturing, you can control the degree of accuracy needed for a feature. A feature is some aspect of a part, such as a point, line, axis, or surface.
You can apply tolerances directly to a dimension by appending the tolerances to the dimension text. These dimension tolerances indicate the largest and smallest permissible size of the dimension. You can also apply geometric tolerances, which indicate deviations of form, profile, orientation, location, and runout (see Adding Geometric Tolerances).
Lateral tolerances can be specified from theoretically exact measurements. These are called basic dimensions and have a box drawn around them.
If the dimension value can vary in both directions, the plus and minus values you supply are appended to the dimension value as deviation tolerances. If the deviation tolerance values are equal, AutoCAD LT displays them with a ± sign and they are known as symmetrical. Otherwise, the plus value goes above the minus value.
If the tolerances are applied as limits, AutoCAD LT uses the plus and minus values you supply to calculate a maximum and minimum value. These values replace the dimension value. If you specify limits, the upper limit goes above the lower.
