4212-366Y MINNESOTA RUBBER QUAD RING

The HQ4212 is an AS568-212 black Buna-N (Nitrile) 70 Shore A Quad-Ring supplied with an inside diameter of 0.859 in (21.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.137 in (28.88 mm). This quad-ring resists spiral failure in reciprocating service thanks to its multi-lobe geometry.

The compound resists many alcohols, water, and propane and butane. Buna-N (Nitrile) is valued for reliable performance in both static and dynamic service, low compression set under sustained load. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). The profile itself contributes a parting line located away from the sealing surface and resistance to the spiral twisting that defeats round-section rings.

Typical settings include fluid power, general industrial maintenance, and agricultural equipment.

Reference part number HQ4212 when ordering; the item is sold individually. Nominal inside diameter is listed as 7/8 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.