The QH70366 is an AS568-366 black Buna-N (Nitrile) 70 Shore A Quad-Ring built to an inside diameter of 7.225 in (183.52 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 7.645 in (194.18 mm). This quad-ring uses a four-lobed profile to create two sealing surfaces per side, reducing the squeeze needed to seal.
Buna-N (Nitrile) offers an economical choice for high-volume maintenance programs, reliable performance in both static and dynamic service. It resists many alcohols, water, and petroleum-based oils. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or strong acids call for a different compound. The profile itself contributes a parting line located away from the sealing surface and two sealing bands per contact face rather than one.
Maintenance and OEM teams specify it across automotive, construction equipment, and general industrial maintenance.
Reference part number QH70366 when ordering; the item is sold individually. Unit weight is approximately 16.115 g and nominal inside diameter is listed as 7 1/4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description Q-366 BUNA 70 Q RING
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 7.225 inch (183.52 mm)
Actual_OD 7.645 inch (194.18 mm)
ProductCode Description O-Rings - Square/Quad - Commodity