Viton 75-257-Black-Pk2

Ordered as SB-V70257-2, this is an AS568-257 black Viton® (FKM) 70 Shore A O-Ring with an inside diameter of 5.859 in (148.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.137 in (155.88 mm). The o-ring compresses into its gland to block fluid or gas migration across a joint. The catalog record notes: 0.139CSX5.859"IDX6.137"OD.

The material holds up against petroleum oils and fuels, many acids, and aromatic hydrocarbons. That behavior comes from the compound itself: Viton® (FKM) is valued for very low compression set at elevated temperature and outstanding high-temperature capability. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where amines or low-molecular-weight organic acids are present.

Maintenance and OEM teams specify it across chemical processing, high-temperature process equipment, and semiconductor equipment.

Stocked as SB-V70257-2 and sold by the bag. Nominal inside diameter is listed as 5 7/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.