1.78MM CS X 9.75MM ID BLACK BUNA 70D

Ordered as H1.78X9.75, this is a black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 9.75 mm (0.384 in), a cross section of 1.78 mm (0.07 in), and an outside diameter of 13.31 mm (0.52 in). The o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.

Expect good resistance to petroleum-based oils, hydraulic fluids, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) is known for an economical choice for high-volume maintenance programs, strong abrasion and tear resistance. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Exposure to strong acids or automotive brake fluid will shorten service life.

You will find this material specified across agricultural equipment, fluid power, and automotive.

Reference part number H1.78X9.75 when ordering; the item is sold individually. Unit weight is approximately 0.0002 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.