Polyurethane (AU/EU) The good mechanical properties of these elastomers - including tensile strength, elongation characteristics, and wear resistance - prove invaluable for 'O' rings used in drive transmissions.
Chemical properties Excellent resistance to oxygen and weathering. Good resistance to hydrocarbon fuels and mineral oils. Resistance to acids and alkalis is low, and some grades are affected by water and humidity.
Typical operating temperatures -15°C to +85°C continuous, or +100°C intermittent.
Fluid sealing duties Stress relaxation above +50°C often precludes these elastomers from sealing applications.
James Walker standard grades Supplied in hardnesses of 55-95 IRHD. Grades are also available in 60-74 hardness Shore D.