Q-312 BUNA 70 Q RING

The QH70312 is an AS568-312 black Buna-N (Nitrile) 70 Shore A Quad-Ring measuring an inside diameter of 0.6 in (15.24 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.02 in (25.91 mm). This quad-ring uses a four-lobed profile to create two sealing surfaces per side, reducing the squeeze needed to seal.

It resists many alcohols, petroleum-based oils, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) is specified for the most widely specified general-purpose sealing elastomer and an economical choice for high-volume maintenance programs. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). It is not the right choice where automotive brake fluid or ketones are present. The profile itself contributes two sealing bands per contact face rather than one and lower compressive load required to achieve a seal.

You will find this material specified across agricultural equipment, general industrial maintenance, and automotive.

QH70312 ships individually. Nominal inside diameter is listed as 5/8 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.