Swordfish 32241 Automotive Self-Centered Bonded Seal/Gasket Assortment, 150 Piece The Bonded Seal was originally designed to replace copper type washers in high-pressure systems The Bonded Seal comprises a metal washer and an elastomeric ring bonded inside the diameter The metal washer prevents over-compression and limits deformation of the elastomeric ring Reliable low and high pressure sealing, High and low temperature capabilities Bolt torque is reduced with no loss of tightening load