Ordered as H50318, this is an AS568-318 black Buna-N (Nitrile) 50 Shore A O-Ring with an inside diameter of 0.975 in (24.77 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.395 in (35.43 mm). The o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.
Buna-N (Nitrile) is known for strong abrasion and tear resistance, the most widely specified general-purpose sealing elastomer. Expect good resistance to petroleum-based oils, hydraulic fluids, and propane and butane. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C).
Maintenance and OEM teams specify it across automotive, agricultural equipment, and hydraulic and pneumatic systems.
Order part number H50318, sold individually. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Description -318 BLACK BUNA 50D O-RING
Actual Cross Section 0.21 inch (5.33 mm)
Actual Inside Diameter 0.975 inch (24.77 mm)
Actual Outside Diameter 1.395 inch (35.43 mm)
Measurement System Imperial
Product Category O-Rings - Bulk - Commodity