NSN 1560-01-655-9589

A flat or preformed item of metallic or nonmetallic material. It may vary in shape and its surface may be smooth and/or serrated. Its thickness is small in comparison to both its length and width. It is designed to be mounted upon a surface or between two surfaces. Its primary function is to strengthen, join, or separate aircraft structural parts. Excludes plate, mending; shim; and spacer, plate.