568-421 PTFE ORINGS FDA

The TFE421 is an AS568-421 white PTFE (Teflon) 55 Shore D O-Ring with an inside diameter of 3.975 in (100.97 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 4.525 in (114.94 mm). This o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

The material holds up against nearly all industrial chemicals, steam, and solvents. That behavior comes from the compound itself: PTFE (Teflon) is widely chosen for excellent dielectric properties and non-stick, non-contaminating surface characteristics. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C).

Maintenance and OEM teams specify it across aggressive-media pipelines, food and beverage, and laboratory equipment.

This item is sold individually under part number TFE421. Nominal inside diameter is listed as 4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.