4445-366Y MINNESOTA RUBBER QUAD RING

HQ4445 is an AS568-445 black Buna-N (Nitrile) 70 Shore A quad profile Quad-Ring measuring an inside diameter of 7.975 in (202.57 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 8.525 in (216.54 mm). In service, this quad-ring resists spiral failure in reciprocating service thanks to its multi-lobe geometry.

Buna-N (Nitrile) is specified here for low compression set under sustained load and economical choice for high-volume maintenance programs. Expect good resistance to many alcohols, hydraulic fluids, and petroleum-based oils. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to ketones or automotive brake fluid will shorten service life.

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

Reference part number HQ4445 when ordering; the item is sold individually. Nominal inside diameter is listed as 8 inch. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.