The H70339 is an AS568-339 black Buna-N (Nitrile) 70 Shore A O-Ring supplied with an inside diameter of 3.225 in (81.92 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 3.645 in (92.58 mm). This o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.
The material holds up against greases and lubricants, petroleum-based oils, and hydraulic fluids. 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. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C).
It sees regular use in automotive, hydraulic and pneumatic systems, and fluid power.
Reference part number H70339 when ordering; the item is sold individually. Unit weight is approximately 7.42 g and nominal inside diameter is listed as 3 1/4 inch. 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 -339 BLACK BUNA 70D O-RING
uf_description2 0.210" (5.33MM) CS X 3.225" (81.92MM) ID
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 3.225 inch (81.92 mm)
Actual_OD 3.645 inch (92.58 mm)
ProductCode Description O-Rings - Bulk - Commodity