Metric TC Rotary Oil Shaft Seal FKM Fluorine Double Lip Seal 56mm - 68mm Shaft

Measure three dimensions on your existing seal or housing: the inner diameter (ID) that contacts the shaft, the outer diameter (OD) that presses into the housing bore, and the depth (width) of the seal groove. Match all three to the variant listed as "Inner Ø x Outer Ø x Depth" in millimetres. If you are replacing an OEM seal, the part number on the old seal often encodes these three dimensions directly.

A TC seal has two sealing lips: a primary lip that retains oil and a secondary lip that excludes dust and contaminants. An SC seal has only a single lip. TC seals are preferred in environments where both fluid retention and contamination exclusion are required — such as wheel hubs, differentials, and gearboxes exposed to road debris or water ingress.

FKM (fluoroelastomer, often sold under the trade name Viton®) offers significantly higher temperature resistance — typically up to 200 °C (392 °F) versus approximately 120 °C (248 °F) for standard NBR. FKM also resists a wider range of synthetic lubricants, ATF fluids, and aggressive chemicals. For high-temperature gearboxes, performance differentials, or applications using synthetic gear oil, FKM is the technically correct choice.

TC rotary shaft seals are designed for rotating shaft applications, not reciprocating (linear) motion. For hydraulic cylinder rods that move in and out linearly, you would need a rod seal or wiper seal with a different lip geometry. However, these TC seals are suitable for the rotating input/output shafts of hydraulic pumps and motors.

Clean the housing bore and shaft journal thoroughly. Lightly lubricate the seal lip with the same oil the seal will retain. Press the seal squarely into the bore using a seal driver or a flat plate of the correct diameter — never hammer directly on the seal face. Ensure the seal sits flush or slightly below the housing face. Avoid nicking the primary lip on shaft keyways or splines during installation; use a sleeve or tape to protect the lip.

Yes. FKM elastomer is compatible with most petroleum-based and synthetic gear oils, automatic transmission fluids (ATF), and many hydraulic fluids. It is not recommended for use with ketone-based solvents, certain brake fluids, or steam. If you are unsure about compatibility with a specific fluid, consult the fluid manufacturer's chemical resistance data for FKM.

For optimal seal life, the shaft journal surface should have a finish of Ra 0.2–0.8 µm (8–32 µin) with a lead-free ground finish. Avoid longitudinal machining marks, which can act as a spiral path for oil to migrate past the lip. Shaft hardness of 45–60 HRC is recommended to resist lip wear over time.