Flat and flanged washers.
These parts are usually supplied in VHDS (very high density silicone) rubber and the full reference should include:
► The letter S
► The appropriate grade which corresponds:
- to the youngs modulus of the rubber under static compression in accordance with ASTM D945 (ref. 33 to 77)
- or to the stiffness measured on a part (ref. 16 to 25)