5.7MM CS X 129.2MM ID BLACK BUNA 70D

Part number H5.7X129.2 is a black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 129.2 mm (5.087 in), a cross section of 5.7 mm (0.224 in), and an outside diameter of 140.6 mm (5.54 in). An o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load.

The material holds up against greases and lubricants, hydraulic fluids, and propane and butane. Buna-N (Nitrile) is widely chosen for strong abrasion and tear resistance, an economical choice for high-volume maintenance programs. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where automotive brake fluid or polar solvents are present.

Maintenance and OEM teams specify it across hydraulic and pneumatic systems, fluid power, and automotive.

H5.7X129.2 ships individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.