Chamfer

A chamfer /ˈʃæm.fər/ is a transitional edge between two faces of an object. It can also be known as a bevel but connotes more often cutting and is more often 45° with respect to the two adjoining faces. If the un-chamfered intersection of the adjoining faces would otherwise form a right angle, 90° as is most common, the chamfer will typically be uniform and pitched at 45°. A fully chamfered square interior would thus be octagonal. (By contrast, a fillet is the rounding off of an interior corner, and a rounding of an exterior corner is called a "round" or a "radius")