The Caterpillar 4H-6520 O‑Ring is a genuine Cat OEM seal molded from nitrile (NBR) rubber with a 75A hardness, built to fit Caterpillar equipment that requires the 4H‑6520 sizing. It measures 183.74 mm inside diameter with a 3.53 mm cross‑section (7.24 in ID and 0.139 in CS). This part is cataloged as Cat 4H-6520 and is designed as the replacement seal for the corresponding Cat assemblies; Cat notes that changes to the manufacturer's configuration may affect fit, so verify the exact specification against your equipment documentation. Use this 4H‑6520 O‑ring when your Cat maintenance or replacement guide calls for the 4H‑6520 size to ensure a reliable seal.
