568-257 PTFE ORINGS FDA

The TFE257 is an AS568-257 white PTFE (Teflon) 55 Shore D O-Ring built to 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). This o-ring delivers dependable bidirectional sealing in a compact groove envelope.

PTFE (Teflon) is specified here for excellent dielectric properties and very wide continuous service temperature range. This material stands up to solvents, oxidizing media, and steam. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where molten alkali metals or elemental fluorine at temperature are present.

Typical settings include semiconductor fabrication, laboratory equipment, and aggressive-media pipelines.

TFE257 ships individually. Nominal inside diameter is listed as 5 7/8 inch. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.