-439 BLACK BUNA 70D O-RING

The H70MD439 is an AS568-439 black Buna-N (Nitrile) 70 Shore A O-Ring supplied with an inside diameter of 6.475 in (164.47 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 7.025 in (178.44 mm). This o-ring remains the most cost-effective sealing element available for pressurized assemblies.

The compound resists water, propane and butane, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) delivers reliable performance in both static and dynamic service, low compression set under sustained load. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where ozone and direct sunlight or strong acids are present.

The compound is metal detectable for HACCP and foreign-body control programs. It sees regular use in agricultural equipment, automotive, and general industrial maintenance.

Order part number H70MD439, sold individually. Nominal inside diameter is listed as 6 1/2 inch. 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.