A shoulder washer can also be known as an insulation sleeve.
The shoulder washer is designed to insulate screws, rivets or wire from an assembly.
Features and Benefits of a shoulder washer
Thermally insulate a screw from making metal to metal contact
Act as Spacers and Guides
Are Strong and Corrosion Resistant
Can be Used as Seal in Some Applications
Why and when to use a shoulder washer?
Shoulder washers can be inserted into a housing to provide a bearing surface for rotary applications.
The flange on the shoulder washer is used to locate the bushing when it is installed or to provide a thrust bearing surface.
Shoulder Washers are used to prevent heat flow through the screw to other parts of the thermal assembly.