Special Features:

Bolt holes are countersunk; spacer is shaped like an arc with a straight back.

Properties:

A metallic or nonmetallic item of various peripheral shapes and a solid cross-section. It is designed to maintain a predetermined distance between two surfaces. It may have flat parallel bearing surfaces. Do not use if a more specific name applies. See also spacer, ring; spacer, plate; spacer, sleeve; spacer, stepped; shim and washer, flat.