To Change the Distance Snap Value Temporarily (AutoCAD Mechanical Toolset)

Click Home tabDimension panelPower Dimension. Find
Specify the first and second extension line origin.
When prompted for the dimension line location, enter P.
When prompted to select an object, enter O. The Placement Options dialog box is displayed.
Select the Use distance snap for placement check box and enter the new snap value in the box.
Note:
The new value entered is applicable only within the existing Power Dimension session.
Click Power Dimensioning tabClose panel Close Editor. Find