Use ChamferBox to create a box with beveled or rounded edges.
Create panel >
(Geometry) > Extended Primitives > Object Type rollout > ChamferBox button
Examples of chamfered boxes
To create a standard chamfered box:
Ctrl to constrain the base to a square.)To create a cubic chamfered box:
On the Creation Method rollout, click Cube.
Beginning at the center of the cube, drag in a viewport to set all three dimensions simultaneously.
Release the button, and move the mouse to set the fillet or chamfer.
Click to create the object.
You can change a cube's individual dimensions in the Parameters rollout.
Forces length, width, and height to be equal. You can change a cube's individual dimensions in the Parameters rollout.
Creates a standard chamfered box primitive from one corner to the diagonally opposite corner, with individual settings for length, width, and height.

Sets the corresponding dimensions of the chamfered box.
Slices off the edges of the chamfered box. Higher values result in a more refined fillet on the edges of the chamfered box.
Sets the number of divisions along the corresponding axis.
Sets the number of segments in the filleted edges of the box. Adding fillet segments increases the edge roundness.
Blends the display of the faces of the chamfered box, creating a smooth appearance in rendered views.
Generates coordinates for applying mapped materials to the chamfered box. Default=on.
Controls the scaling method used for texture mapped materials that are applied to the object. The scaling values are controlled by the Use Real-World Scale settings found in the applied material's Coordinates rollout. Default=off.