Duramax Marine

“Delivering world-class marine and industrial product solutions designed for superior performance and durability.”

Duramax Marine® is one of the most well-known names in the Maritime Industry. With over 100 years of customer service engineering solutions for the recreational, commercial and military marine markets, and industrial pump markets, they are a trusted manufacturer, keen to offer the most efficient and robust solutions for your vessel needs.

Duramax Marine® is the global leader in water-lubricated bearing systems:

Johnson Cutless® Water Lubricated Rubber Bearings:




Precision Machined naval brass shell featuring specially formulated molded nitrile rubber that meets MIL-DTL-17901C(SH) Class II type bearing specifications. Over 100 different sizes in stock (inch and metric). Custom sizing and materials can be requested for unique applications.

DMX®-LSS – Polymer Alloy Locking Stave System:

Revolutionary alloy bearing can be used in a 2:1 or less L/D configuration. Tests confirm DMX® performs better than US Military Specification MIL-DTl+17901C(SH) requirements. Runs extremely well at low shaft speeds without noise, vibration, or stick-slip. It has a low coefficient of friction at breakaway and a full range of shaft speeds. Dry run capable in event of water shut down.

Romor® I - Advanced Rubber Stave System:

Non-polluting. Meets MIL-DTl+17901C(SH) Class III specifications. Specially formulated nitrile rubber permanently bonded to ultra-high molecular weight polyethylene (UHMW-PE) backing. The bearing surface is engineered with a controlled thickness, 15 to 20 micro-inch glass-smooth finish and 80 Durometer, Shore A hardness, providing a lower coefficient of friction, quiet operation and longer bearing and shaft life.

Johnson® Demountable Rubber Bearings:

They are tough, molded, nitrile rubber staves that are used in more than 2000 installations operating worldwide. They allow for bearing change out without shaft or propeller removal, reducing maintenance time and cost. Choice of bearing sizes available for each bearing housing diameter.

Durablue® Self-Lubricated Composite Marine Bearings:


Non-polluting, water-lubricated stern tube bearings are manufactured using a unique synthetic reinforced composite that incorporates solid lubricants for superior operation and outstanding wear life in blue water applications. The composite resin matrix was designed to withstand the rigors of seawater operation and frictional heat generated when used in stern tube propulsion systems.

DryMax® Stern Tube and Rudder Sealing System:

A reliable system that uses no grease or oil and is easy to install and maintain, and is engineered to protect the environment.

Duramax Marine® custom heat exchangers and batterboard systems that keep your vessel cool and protected.

Duracooler® Keel Coolers:

A series of engineered flow diverter “scoops” are built along the width of the bottom edge that helps increase heat transfer efficiency by more than 17%. One-piece design makes it easier to install and 90/10 copper- nickel construction resists water flow erosion and acts as an antifoulant. Available in through-hull or flange-mount installations.

Duracooler® Supr-Stak™ Keel Coolers:

The most efficient keel cooler, “jets” seawater in a tunnel-like configuration between its upper and lower tube assemblies. Innovative design advancements have been engineered to both greatly enhance and optimize turbulent flow outside and around the keel cooler using Computational Fluid Dynamic (CFD) modeling techniques. Tested and validated utilizing a full-scale water tunnel.

Demountable Keel Cooler :


Our 90/10 Copper/Nickel spiral tubing is resistant to salt water corrosion and sea growth, and gives superior heat transfer. Its demount-able, modular design is available in 4, 6, 8, 12, and 24 tube units that can be combined to cool multiple circuits. No inboard sea chest or through-hull fittings are needed, which makes for easy installation.

BoxCooler Keel Cooler :

Operates in a sea chest within your vessel protected against underwater hazards. Able to meet the cooling needs of your engines as well as other multiple heat sources. Cooler tubes are coated with a heat-cured, synthetic coating that protects against galvanic corrosion. Impressed Current Anti-fouling System (ICAF) resists biological marine growth

Duramax® Linerite® Composite Batterboard System :

Linerite has a 0.12 low-coefficient of friction UHMW-PE facing and proprietary energy-absorbing composite core, fused together at the molecular level. LINERITE® is environmentally friendly, not affected by chemicals, marine organisms or freezing temperatures. LINERITE® can be pre-curved and is available in standard black and yellow, or can be matched to any custom color.

Johnson® Commercial Dock Bumpers and Fendering :

We only use high-quality EPDM rubber available in black and non-marking grey and white. It is unaffected by ozone, allowing EPDM to perform up to 4X longer.