*4381-366Y MINNESOTA RUBBER QUAD RING

This quad-ring is supplied in AS568-381 black Buna-N (Nitrile) 70 Shore A built to an inside diameter of 11.975 in (304.17 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 12.395 in (314.83 mm), catalogued under part number HQ4381. It uses a four-lobed profile to create two sealing surfaces per side, reducing the squeeze needed to seal.

Buna-N (Nitrile) is widely chosen for an economical choice for high-volume maintenance programs and low compression set under sustained load. It resists hydraulic fluids, propane and butane, and water. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). The profile itself contributes two sealing bands per contact face rather than one and lower compressive load required to achieve a seal.

Maintenance and OEM teams specify it across agricultural equipment, hydraulic and pneumatic systems, and construction equipment.

Reference part number HQ4381 when ordering; the item is sold individually. Review your operating media and conditions against this specification before installation. 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.