5.7MM CS X 255MM ID BLACK BUNA 70D

Ordered as H5.7X255, this is a black Buna-N (Nitrile) 70 Shore A O-Ring supplied with an inside diameter of 255 mm (10.039 in), a cross section of 5.7 mm (0.224 in), and an outside diameter of 266.4 mm (10.49 in). The o-ring remains the most cost-effective sealing element available for pressurized assemblies.

Buna-N (Nitrile) is valued for reliable performance in both static and dynamic service, low compression set under sustained load. The material holds up against water, hydraulic fluids, and petroleum-based oils. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Applications involving ozone and direct sunlight or polar solvents call for a different compound.

Maintenance and OEM teams specify it across fluid power, automotive, and agricultural equipment.

Reference part number H5.7X255 when ordering; the item is sold individually. Unit weight is approximately 25.533 g. Check the compound against your process media, pressure and temperature before committing to a design. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.