Other seals

How to select the size

The key dimension is the shaft diameter. The other numbers in the part code are the seating diameter and width.

A V-ring needs no groove and fits onto the shaft without dismantling the assembly, which simplifies repair.

Materials

The material is chosen by medium and temperature, not by price:

• NBR — the standard for mineral oil, −30…+100 °C. Most common and least expensive.
• FKM (Viton) — up to +200 °C, aggressive media, brake fluid. Three to five times the price of NBR.
• PU (polyurethane) — high pressure and abrasion, but not above +80 °C.
• PTFE — chemicals, very low friction, but poor under compression without support.
• EPDM — water, steam, glycol-based brake fluid. Not compatible with oil.

Common fitting mistakes

Three mistakes that make a new seal leak within a day:

1. Damaged lip during fitting. The seal is pushed over threads or splines without a sleeve — the lip is cut and you cannot see it.
2. Measuring a worn part. The old ring has lost its shape, so the new size does not seat in the groove.
3. No back-up ring. Above 160 bar the seal extrudes into the gap.

Frequently asked questions

Is a V-ring a contact seal?
No. The lip is not continuously pressed against metal, so it barely wears the shaft and works at high speed.

Can a V-ring replace a lip seal?
No. A V-ring keeps dirt and splash out but does not hold pressure or retain a full oil level.

What if the shaft is worn?
A V-ring tolerates some shaft wear, unlike a lip seal. For deep wear, restore the shaft or fit a repair sleeve.