8400 SERIES 2 9/16 X 3 X 7/32W U CUP

NU8407-0256 is a Buna-N (Nitrile) U-Cup U-Cup Seal with a 2-9/16 inch inside diameter, a 3 inch outside diameter, and a height of 7/32 inch. In service, this u-cup seal uses a U-shaped profile that system pressure forces outward, tightening the seal as pressure rises.

This material stands up to water, greases and lubricants, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for low compression set under sustained load, reliable performance in both static and dynamic service. Exposure to polar solvents or ketones will shorten service life.

Typical settings include automotive, general industrial maintenance, and construction equipment.

This item is sold individually under part number NU8407-0256. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.