The H50357 is an AS568-357 black Buna-N (Nitrile) 50 Shore A O-Ring measuring an inside diameter of 5.475 in (139.07 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.895 in (149.73 mm). This o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.
Buna-N (Nitrile) is specified here for strong abrasion and tear resistance, low compression set under sustained load. The compound resists propane and butane, hydraulic fluids, and greases and lubricants. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Exposure to automotive brake fluid or polar solvents will shorten service life.
You will find this material specified across construction equipment, general industrial maintenance, and fluid power.
This item is sold individually under part number H50357. Nominal inside diameter is listed as 5 1/2 inch. Review your operating media and conditions against this specification before installation.
Description -357 BLACK BUNA 50D O-RING
Actual Cross Section 0.21 inch (5.33 mm)
Actual Inside Diameter 5.475 inch (139.07 mm)
Actual Outside Diameter 5.895 inch (149.73 mm)
Measurement System Imperial
Product Category O-Rings - Bulk - Commodity