Ordered as QH70039, this is an AS568-039 black Buna-N (Nitrile) 70 Shore A quad profile Quad-Ring with an inside diameter of 2.739 in (69.57 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 2.879 in (73.13 mm). The quad-ring resists spiral failure in reciprocating service thanks to its multi-lobe geometry.
As a material, Buna-N (Nitrile) is known for low compression set under sustained load and the most widely specified general-purpose sealing elastomer. Expect good resistance to many alcohols, water, and petroleum-based oils. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Exposure to ketones or polar solvents will shorten service life.
Maintenance and OEM teams specify it across hydraulic and pneumatic systems, general industrial maintenance, and fluid power.
This item is sold individually under part number QH70039. Unit weight is approximately 0.6993 g. Check the compound against your process media, pressure and temperature before committing to a design. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description *Q-039 BUNA 70 Q RING
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 2.739 inch (69.57 mm)
Actual_OD 2.879 inch (73.13 mm)
ProductCode Description O-Rings - Square/Quad - Commodity