1.78MM CS X 11.91MM ID BLACK BUNA 70D

The H1.78X11.91 is a black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 11.91 mm (0.469 in), a cross section of 1.78 mm (0.07 in), and an outside diameter of 15.47 mm (0.61 in). This o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

The material holds up against petroleum-based oils, greases and lubricants, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for low compression set under sustained load, reliable performance in both static and dynamic service. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in strong acids or polar solvents.

Maintenance and OEM teams specify it across general industrial maintenance, hydraulic and pneumatic systems, and construction equipment.

Stocked as H1.78X11.91 and sold individually. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.