Metric O-Rings are employed in specialized applications and, like the name suggests, are standardized by metric dimensions. With a wide variety of sizes available, Metric O-Rings fill in the gaps left by the standardized AS568 o-ring chart. Metric O-Ring sizing is determined by the o-ring's inside diameter and cross section width.

Polyurethane is also known as urethane, cast urethan and millable urethane. Exceptional tensile strength. Abrasion and low temperature resistance. Typical applications include hydraulic seals, gaskets, diaphragms, hoses, and wheels for skate boards. For more information, please see: Comparison Properties Chart, PTFE Encapsulated O-rings, Material Shelf Life, and O-ring Groove Design Chart.