Buna 70-240-Black-Pk25

Ordered as SB-H70240-25, this is an AS568-240 black Buna-N (Nitrile) 70 Shore A O-Ring with an inside diameter of 3.734 in (94.84 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.012 in (101.9 mm). The o-ring delivers dependable bidirectional sealing in a compact groove envelope. The catalog record notes: 0.139CSX3.734"IDX4.012"OD.

The material holds up against petroleum-based oils, greases and lubricants, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) is known for reliable performance in both static and dynamic service, an economical choice for high-volume maintenance programs. 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 polar solvents are present.

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

This item is sold by the bag under part number SB-H70240-25. Nominal inside diameter is listed as 3 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. 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.