Q-351 BUNA 70 Q RING

This quad-ring is supplied in AS568-351 black Buna-N (Nitrile) 70 Shore A with an inside diameter of 4.725 in (120.02 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.145 in (130.68 mm), catalogued under part number QH70351. It seats in a standard o-ring gland while offering improved dynamic performance.

It resists water, petroleum-based oils, and greases and lubricants. Buna-N (Nitrile) offers reliable performance in both static and dynamic service, strong abrasion and tear resistance. 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 automotive brake fluid or ozone and direct sunlight are present. The profile itself contributes resistance to the spiral twisting that defeats round-section rings and two sealing bands per contact face rather than one.

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

QH70351 ships individually. Unit weight is approximately 10.739 g and nominal inside diameter is listed as 4 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.