Buna 70-257-Black-Pk10

Ordered as SB-H70257-10, this is an AS568-257 black Buna-N (Nitrile) 70 Shore A O-Ring with an inside diameter of 5.859 in (148.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.137 in (155.88 mm). The o-ring compresses into its gland to block fluid or gas migration across a joint. The catalog record notes: 6.125IDX5.875"ODX.125"CS.

The compound resists propane and butane, greases and lubricants, and water. Buna-N (Nitrile) is valued for an economical choice for high-volume maintenance programs, strong abrasion and tear resistance. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Applications involving automotive brake fluid or polar solvents call for a different compound.

It sees regular use in fluid power, construction equipment, and hydraulic and pneumatic systems.

Order part number SB-H70257-10, sold by the bag. Check the compound against your process media, pressure and temperature before committing to a design.