3MM CS X 39.5MM ID BLACK BUNA 70D

Part number H3X39.5 is a black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 39.5 mm (1.555 in), a cross section of 3 mm (0.118 in), and an outside diameter of 45.5 mm (1.79 in). An o-ring compresses into its gland to block fluid or gas migration across a joint.

The compound resists greases and lubricants, many alcohols, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) is specified for an economical choice for high-volume maintenance programs, 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). Applications involving strong acids or ozone and direct sunlight call for a different compound.

You will find this material specified across general industrial maintenance, agricultural equipment, and hydraulic and pneumatic systems.

Reference part number H3X39.5 when ordering; the item is sold individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.