Stern tube seals


Every 5 years the stern tube seals of your vessel need to be overhauled during dry dock. We are specialized in and are an independent supplier of, stern tube seal spare parts. More than 10 years of experience in installing stern tube seal spare parts worldwide. The stern tube seals that we supply are made of FKM (Viton) or HNBR and fit in lip seal systems of all major brands, which means they fit all regular Air and oil-lubricated systems. Learn more about our stern tube seal spare part range, brands, and types further down this page.

What is a stern tube?

It is a tube that directs the propeller shaft from the inside of the vessel to the outside. In the stern tube there are sleeve bearings that carry the shaft. The stern tube bearings can be lubricated by oil or water, depending on the design.

What is the function of stern tube seals?

The primary function of a stern tube seal is, to keep the seawater out of the vessel and to keep the oil in the stern tube. Seawater ingress into the stern tube can damage the stern tube bearings and losing oil leads to environmental pollution.

Stern tube seals

Stern tube seals & installation kits

  • Made of High-grade FKM material (commonly referred to Viton©),
  • For certain makes HNBR material is available,
  • Delivery from stock,
  • For urgent shipments please call +31 85 0706610.
Stern tube seal types

Brands and types stern tube seal spares:

  • Compatible with Simplex®,
  • Compatible with Kemel®,
  • Compatible with Kobelco®,
  • Compatible with Wärtsilä®,
  • Compatible with Lagersmit ® and more…
Distance ring

Chrome steel Liners & distance rings

  • AFT & FWD chrome steel liners,
  • AFT Chrome steel liners delivered from stock,
  • Reconditioning of old liners,
  • Distance-/ spacer rings.

Stern Tube Seals and Installation Kits

We supply stern tube seals that are made of a high-grade FKM material (commonly known as Viton®) and comply with the maker’s fitting tolerances.

In addition, we also have stern tube seals made of HNBR (Perbunan S®) material in our range. In comparison to FKM (Viton®), HNBR material may not be used with Bio-oil. HNBR material is only suitable for mineral oils. While FKM (Viton®) is suitable for both oil types, Bio oils (EAL oils) and mineral oils.

One other key point of FKM (Viton®) material is that it is highly resistant to heat and a wide variety of different liquids.

Essential to learn is, that our stern tube seals fit Air and Oil lubricated lip seal systems.

Together with the stern tube seal spare parts, we offer a complete installation kit. An installation kit contains liner o-rings, o-rings for oil lines, gaskets, anodes, and fasteners. This installation kit includes all the small components you need for a complete stern tube seal overhaul.


To summarize our stern tube seal spare parts are:

  • Available from stock,
  • Available in FKM (Viton) and HNBR (Perbunan S®) Materials,
  • Suitable for Air seal systems,
  • Suitable for Bio-oil (EALs) and Mineral Oil
  • Suitable for Oil lubricated lip seal system,
  • Made according to our design, based on many years of field experience,
  • Equal or better quality than OEM spare parts,
  • Provided with a one-year warranty.

A cost-efficient solution, independent from the maker!


seals for stern tube
10 years  anniversary RM Propulsion

Brands and types of stern tube seals

The spare parts that we supply are compatible with the below-mentioned brands and types, moreover, they fit into Air and oil-lubricated lip seal systems. This means you can rely on us for all common brands of Stern tube seals.


  • SKF Simplex®  AirSpace, Compact SC-1, Compact 2000, and Compact SC-2 types.
  • Kobelco® C, CX, DX, and AX types.
  • Kemel® C, CX, DX stern tube systems.
  • Wärtsilä® Airguard and MK-2 types.
  • Lagersmit® Supreme Seaguard Ventus
  • IHC Lagersmit® Supreme types.
  • Lips® MK-2 types.
  • John Crane® MK-2 types.
  • Waukesha® MK-2 types.
  • Chuetsu® MK-2 types.
  • Dover Japan® MK-2 types.
  • JMT (Japan Marine Technology)® MK-2 types.
  • Deep-Sea Seals® MK-2 types.

Class accepted stern tube seal spare parts and service.

Stern tube seal stock

RM Propulsion B.V.

Neutronweg 45
1627LG, Hoorn
The Netherlands

Contact Us

+31 (0)85 070 6610

RM Propulsion ISO9001