Belleville washers have a slightly conical shape and are used in applications where heavy load bearing is required. The can be used singularly or stacked to increase the load they can bear.
Cup washers are designed to protect the head of a metal screw from electrical contact.
Finishing washers are used to insulate, protect, and give a “finished” look. They are often paired with oval head screws.
Flat washers are the most economical choice when your application calls for spacers, shims, or reinforcements. They spread a load and, depending upon material type, can provide some sort of insulation.
Lock washers are designed to prevent a bolt or screw from turning or loosening in response to shock or vibration. They can have external or internal teeth for gripping power, or they may be split washers, which have a ring split at one point in the circle that causes the washer to exert a force between the fastener and the item being fastened and prevents the fastener from loosening.
Retaining washers have a specially shaped center that grips the screw shank tightly. The washer slides on the screw easily, but is retained to the shank.
Sealing washers have a sealant on underside of the washer which helps prevent leakage, contain pressure, and exclude contamination.
Shoulder washers insulate a screw, shaft, rivet or wire from a surface, and are frequently used to dampen vibration.
Slotted washers have a slot across one side of the washer so that they can be slipped on and installed or removed without removing a nut or bolt.
Spring washers are curved with one bend and are excellent for light loads in small spaces. They are often used to absorb axial end-play.
Wave washers and wave springs are curved to absorb shock and vibration, and they also resist loosening and fatigue. These washers are frequently used in applications with limited radial space.