APG stocks the H4X270, a black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 270 mm (10.63 in), a cross section of 4 mm (0.157 in), and an outside diameter of 278 mm (10.94 in). An o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load.
The compound resists greases and lubricants, many alcohols, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) delivers the most widely specified general-purpose sealing elastomer, reliable performance in both static and dynamic service. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where automotive brake fluid or ozone and direct sunlight are present.
It sees regular use in construction equipment, hydraulic and pneumatic systems, and agricultural equipment.
This item is sold individually under part number H4X270. Unit weight is approximately 13.128 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Description 4MM CS X 270MM ID BLACK BUNA 70D
Actual Outside Diameter 278 mm (10.94 inch)
Actual Cross Section 4 mm (0.157 inch)
Actual Inside Diameter 270 mm (10.63 inch)
Measurement System Metric
Product Category O-Rings - Metric - Commodity