There are thousands of different materials used for Washers and Gaskets and they each have special qualities for their application. Some materials, even though they look similar, have better Weathering Properties, Temperature, Strength, Chemical Resistance and so on.
Here is a selection of materials we commonly use ;
RED FIBRE, BLACK FIBRE, GREY FIBRE, COMMERCIAL RUBBER, NEOPRENE, NITRILE, FELT, LEATHER, CNAF[COMPRESSED NON ASBESTOS FIBRE], CORK, GASKET PAPER, ALUMINIUM, COPPER, MILD STEEL, BRASS, NYLON, POLYTHENE, SILICONE, PTFE, PLASTICS…..