Object snaps constrain point specification to exact locations, such as a midpoint or an intersection, on existing objects. Using object snaps is a quick way to locate an exact position on an object without having to know the coordinate or draw construction lines. For example, you can use an object snap to draw a line to the center of a circle or to the midpoint of a polyline segment. You can specify an object snap whenever AutoCAD prompts for a point.
If AutoSnap™ is turned on, AutoCAD displays a marker and a tooltip whenever you move the target box over a snap point. This feature provides a visual clue that indicates which object snaps are in effect.
There are a variety of ways to turn on object snaps. If you choose an individual object snap on the toolbar or enter its name on the command line, the snap stays in effect only for the next point you specify. You also can set running object snaps, that is, one or more object snaps that remain in effect as you work. Choose None to turn off both single and running object snaps.
Snap to a Single Point
When you specify an object snap, the cursor changes to an object snap target box. When you select an object, AutoCAD snaps to the eligible snap point closest to the center of the target box, or aperture.
The object snap buttons are located on the Object Snap flyout on the Standard toolbar.
Use Running Object Snaps
If you need to use the same object snap repeatedly, you can set it as a running object snap, which means it stays on until you turn it off. For example, you might set Center as a running object snap if you need to connect the centers of a series of circles with a line. As with single object snaps, the aperture, or target box, indicates that an object snap is on and identifies the selection area. You can change the size of the target box.
When you turn on multiple running object snaps, AutoCAD uses the object snap most appropriate to the object you select. If two potential snap points fall within the selection area, AutoCAD snaps to the eligible point closest to the center of the target box.
To snap to a geometric point on an object
- At the prompt for a point, hold down SHIFT and right-click in the drawing area. Then choose the object snap you want to use.
- Move your cursor over the desired snap location.
If AutoSnap is on, your cursor automatically locks onto the snap location you selected, and a marker and tooltip indicates the snap point.
- Select an object.
The cursor snaps to the eligible location closest to your selection. Press SHIFT and right-click (for object snap menu).
To set running object snaps
- From the Tools menu, choose Drafting Settings.
- In the Drafting Setting dialog box, Object Snap tab, select the object snaps you want to use.
- To change the size of the target box, choose Options.
- In the Options dialog box, Drafting tab, drag the slider bar under Aperture Size.
- Choose OK to exit each dialog box.
Press SHIFT and right-click to display the object snap menu.
To turn on and turn off running object snaps as you work
- On the status bar, click Osnap.
If running object snaps have been set, the previous settings are turned on or off. You can also press
to toggle running object snaps.