Buna 70-243-Black-Pk25

Ordered as SB-H70243-25, this is an AS568-243 black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 4.109 in (104.37 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.387 in (111.43 mm). The o-ring delivers dependable bidirectional sealing in a compact groove envelope. Source specification: 0.139CSX4.109"IDX4.387"OD.

The compound resists propane and butane, many alcohols, 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. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C).

Typical settings include construction equipment, fluid power, and agricultural equipment.

Reference part number SB-H70243-25 when ordering; the item is sold by the bag. Nominal inside diameter is listed as 4 1/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.