*4004-366Y MINNESOTA RUBBER QUAD RING

The HQ4004 is an AS568-004 black Buna-N (Nitrile) 70 Shore A Quad-Ring with an inside diameter of 0.07 in (1.78 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.21 in (5.33 mm). This quad-ring seats in a standard o-ring gland while offering improved dynamic performance.

Buna-N (Nitrile) is specified here for reliable performance in both static and dynamic service, low compression set under sustained load. This material stands up to petroleum-based oils, hydraulic fluids, and water. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where ozone and direct sunlight or strong acids are present. The profile itself contributes lower compressive load required to achieve a seal and resistance to the spiral twisting that defeats round-section rings.

Maintenance and OEM teams specify it across automotive, agricultural equipment, and fluid power.

HQ4004 ships individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.