To open the Scale Tool, click the Scale Tool icon 
in the Tool Box.
Scale Tool options
Choosing a coordinate system for the Scale Tool
Use the Tool Settings window to specify the coordinate system (Scale Axis) for the Scale Tool.
Unlike the Move Tool, you can only key scale operations in Object space.
When you scale an object on all 3 axes simultaneously, the transformation always occurs in Object space, regardless of the current setting.
You can only scale objects without components (for example, joints) in Object space.
- Axis Orientation
- Specifies the coordinate system for the Scale Tool.
- Object
-
Scales an object in object space coordinate system. Axis orientation includes rotations on the object itself. If several objects are selected, each object scales the same amount relative to its own object space coordinate system.
- World
-
Scales in the world space coordinate system. The object is aligned to the world space axis. This is the default.
- Component
-
Scales selected vertices or CVs along the average of their combined normals.
- Parent
-
Aligns the object to the rotation of the parent object. Scaling is constrained to those axes in the local space coordinate system. The object is aligned to the rotation of the parent object and does not include the rotations on the object itself. If several objects are selected, each object scales the same amount relative to its own object space coordinate system.
Note: In Maya 2015 and earlier versions, Parent mode was called Local mode. - Normal
-
Scales selected vertices or CVs in the U or V direction of the surface. Typically you would use this option for small sets of CVs. The manipulator indicates the surface Normal, U, and V directions.
- Along rotation axis
-
Aligns to the Rotate Tool’s axes on the object. If you have set the Rotate Axis in the object’s Transform Attributes to a different value (which offsets the orientation of the object relative to the orientation of the object's local rotation axis) this attribute will have an affect; otherwise, Along Rotation Axis is the same as Object.
- Along live object axis
-
(This setting does not work with Reflection on.) Sets the Scale Tool to move objects along the axis of a live object. Most commonly, you would make a construction plane live, but any object can be set live. When you have a live object and select this option, the move arrows of the Move Tool align to the live construction plane. (The geometry of the live object doesn’t matter; the move aligns to the axes of the live object.)
- Custom
-
Lets you set a custom orientation . Custom axis orientation is automatically selected when you activate custom pivot editing mode. The offset coordinates update as you edit the orientation of the custom pivot. See Activate custom pivot editing mode.
- Set Orientation to Component
-
Lets you orient the Scale Tool's X-axis by selecting a component in the scene. See Set a custom axis orientation.
Note: Set Orientation to Component replaces Set to Point, Set to Edge, and Set to Face. - Edit Pivot
-
Activates custom pivot editing mode. See Activate custom pivot editing mode.
- Reset
-
Resets the custom pivot's position and orientation. See Reset the custom pivot.
- Scale pivot
-
Lets you scale object components about the object’s pivot point.
- Default
- Lets you scale the selected objects about each object's individual pivot point. Note: In component selection mode, all objects scale about a pivot point in the center of the selection.
- Object
- Lets you scale the selected objects about each object's individual pivot point.
- Manip
- Lets you scale all selected objects using the manipulator as a pivot point.
- Preserve Child Transform
-
When on, moving a parent object does not move its children.
- Preserve UVs
-
When this option is selected, moving components in the scene view causes the corresponding UVs to move accordingly in the UV space. The net result is that the texture does not become warped.
- Pin Component Pivot
-
When on, locks your edits to the custom pivot in place, letting you use the same custom pivot to transform different components on one mesh. See Pin the custom pivot.Note: Pivot pinning is only available when a custom pivot has been set. See Change the pivot point.
- Prevent Negative Scale
-
When on, Maya disables negative scaling of components. Scaling along each axis is limited to positive values.Note: Prevent Negative Scale does not support objects.
- Discrete Scale
-
The Discrete Scale setting enables the Relative option and lets you specify the amount an object is scaled in increments (determined by the Step Size value).
- Relative
-
While Maya scales the object, relative spacing is maintained. Turn this option off if you don’t want to preserve relative spacing while scaling.
- Step size
-
Enter a value to determine the amount an object is scaled in increments when the Discrete Scale option is selected.
Common Selection Options
- Selection Style
- Determines what happens when you drag the mouse in the scene panel.
- Marquee
-
When you drag your cursor over components in the scene, a marquee appears. When you release the mouse button, components within the marquee are selected.
Tip:
You can quickly toggle selection styles. Holding Tab after making a marquee selection temporarily activates Tab Drag select, letting you quickly add and remove components from your existing marquee selection. See Resize a marquee selection with drag select. - Camera based selection
-
When on, you can only select components that are not obstructed by other components relative to the current camera.
- Drag
-
When you drag the mouse in the scene panel, components under the cursor are selected.
If Camera based paint selection is enabled, you can only select components that are not obstructed by other components relative to the current camera.
- Highlight backfaces
-
When on, backfacing components are highlighted for preselection and can be selected. When this option is off, backfacing components can still be selected, but they are not highlighted for preselection. See Highlight components before selecting them.