**4221-366Y MINNESOTA RUBBER QUAD RING

Ordered as HQ4221, this is an AS568-221 black Buna-N (Nitrile) 70 Shore A Quad-Ring built to an inside diameter of 1.421 in (36.09 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.699 in (43.15 mm). The quad-ring delivers lower friction and better sealing stability than a comparable round-section o-ring.

This material stands up to water, petroleum-based oils, and greases and lubricants. That behavior comes from the compound itself: Buna-N (Nitrile) is specified for low compression set under sustained load and the most widely specified general-purpose sealing elastomer. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where polar solvents or automotive brake fluid are present. The profile itself contributes a parting line located away from the sealing surface and two sealing bands per contact face rather than one.

You will find this material specified across hydraulic and pneumatic systems, construction equipment, and agricultural equipment.

Reference part number HQ4221 when ordering; the item is sold individually. Nominal inside diameter is listed as 1 7/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.