**4389-366Y MINNESOTA RUBBER QUAD RING

Ordered as HQ4389, this is an AS568-389 black Buna-N (Nitrile) 70 Shore A Quad-Ring built to an inside diameter of 19.953 in (506.81 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 20.373 in (517.47 mm). The quad-ring resists spiral failure in reciprocating service thanks to its multi-lobe geometry.

The compound resists propane and butane, water, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for an economical choice for high-volume maintenance programs, reliable performance in both static and dynamic service. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to strong acids or automotive brake fluid will shorten service life. The profile itself contributes resistance to the spiral twisting that defeats round-section rings and lower compressive load required to achieve a seal.

Common environments for this compound include hydraulic and pneumatic systems, agricultural equipment, and automotive.

HQ4389 ships individually. Nominal inside diameter is listed as 20 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.