Part number H4.5X74 is a black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 74 mm (2.913 in), a cross section of 4.5 mm (0.177 in), and an outside diameter of 83 mm (3.27 in). An o-ring compresses into its gland to block fluid or gas migration across a joint.
The material holds up against hydraulic fluids, propane and butane, and greases and lubricants. Buna-N (Nitrile) is known for reliable performance in both static and dynamic service, strong abrasion and tear resistance. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving ketones or strong acids call for a different compound.
You will find this material specified across automotive, general industrial maintenance, and hydraulic and pneumatic systems.
This item is sold individually under part number H4.5X74. Check the compound against your process media, pressure and temperature before committing to a design. 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.
Description 4.5MM CS X 74MM ID BLACK BUNA 70D
Actual Outside Diameter 83 mm (3.27 inch)
Actual Cross Section 4.5 mm (0.177 inch)
Actual Inside Diameter 74 mm (2.913 inch)
Measurement System Metric
Product Category O-Rings - Metric - Commodity