For over 25 years, RS Clare has led the way in the manufacture of curved rail grease. As the UK’s leading supplier, we’re the partner of choice for Network Rail, London Underground and most of the country’s light rail networks. Now expanding into markets around the world, RS Clare is fast becoming the name most associated with advanced and effective curved rail protection.

Engineered to the specific challenges encountered in application

Our curved rail grease achieves outstanding performance through focused research, development and engineering towards the challenges experienced at the wheel/rail interface. These challenges include: 

Our Curved Rail Lubricants

A non-toxic, readily biodegradable curved rail grease for application via trackside lubricators, formulated with extreme pressure and anti-wear additives for enhanced performance capabilities.

A readily biodegradable curved rail grease, Metro Bio Grease is designed for use in underground metro and subway networks and offers enhanced safety features including enhanced fire/smoke resistance and low fume toxicity. 

Our most economic curved rail grease, designed for use in trackside lubricators wherever there is a need for high performance and consistent delivery over a wide temperature range.

A high performance, excellent value, multi-season curved rail grease for trackside lubricators designed for high traffic networks and heavy axle loads, particularly Class I railroads.

Our EcoCurve Range Curved Rail Lubricants

EcoCurve Trackside is an environmentally friendly, high performance curved rail lubricant appropriate for use in all types of trackside lubricators. Designed to protect the gauge corner, EcoCurve Trackside is also suitable for lubricating switchplates and check rails.

EcoCurve Heavy Haul is a premium gauge face lubricant for application via trackside lubricators. Specially formulated to provide enhanced lubrication and protection for curved rails over long distances where heavy loads and high volumes of traffic require an extreme performance, all-seasons curved rail grease.

EcoCurve High Mobility is a unique and innovative curved rail grease designed specifically to provide increased pumpability in trackside applications where there are greater distances between lubricators and grease dispensing units (GDU) than typically encountered, for example narrow tunnels or bridges.

Specialist Solution

The first to design a specialist solution to wear reduction at the wheel-rail interface, our range has grown to offer a comprehensive selection of highly advanced greases that work with all types of lubricator technologies. Since the application of curved rail grease is a total loss system, we take our environmental responsibility very seriously, and have developed a range of biodegradable, non-toxic greases.

Case Study

The tight radius curves at St Pancras Station have long caused issues with noise and garnered complaints from the local residents. After discussions with our technical sales manager, Claretech Supreme was recommended and successfully trialled. Now, it's used in all of their lubricators and continues to manage the noise issue.

Product Selector

Product Description Delivery Method Download TDS

For use in trackside lubricators wherever there is a need for high performance and consistent delivery over a wide temperature range.


High performance multi-season curved rail grease for trackside lubricators. Suitable for high traffic networks and heavy axle loads.


Non toxic, readily biodegradable curved rail grease for trackside lubricators, with excellent EP and Anti-Wear properties.


For use in trackside curved rail lubricators, wherever there is a requirement for high performance and environmentally sensitive products.


For use in trackside curved rail lubricators, wherever there is a requirement for extreme performance and environmentally sensitive products. Designed for high volume and high load rail systems.


Readily biodegradable, fire resistant, low toxicity curved rail grease, for use in Underground and Metro networks and tunnels.


For use in centralised distribution trackside lubricators. All the technical and environmental performance of EcoCurve Trackside, but designed to provide pumpability through narrow bores and long pipe runs whilst still forming a firm grease bead at the GDU.


For use in on-board spray equipment wherever there is a requirement for high performance and environmentally sensitive products. Particularly suited to sensitive and high visibility urban sites


Download Our Rail Lubrication Brochure

Our range of Rail friction management solutions includes Ecolabel accredited curved rail grease, top of rail friction modifiers, gauge face greases, lubricants for infrastructure and application equipment. 

Explore our full range of high-performance rail lubricants in our Rail Lubrication brochure.

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Read our green grease guide to find out more about how environmental performance is defined and measured for rail greases, and understand the importance of environmentally friendly lubricants for track lubrication. 

Track Piece 3 (curved)



What makes the perfect Flange Lubricant?

A high performing rail curve grease must have very distinct characteristics to ensure it meets challenging operational needs. These include extending the life of assets, reducing maintenance costs and time spent on track for corrective maintenance.

RS Clare have been formulating and developing specialist rail curve greases for over 50 years, and using this experience we have developed a list of 12 key characteristics that are essential.


The lubricant should ensure low coefficient of friction (CoF) at the wheel/rail interface, typically less than 0.15. The lower the value, the lower the friction which helps minimise wheel and rail wear.


It is essential to maximise the temperature range over which a lubricant’s performance remains consistent. High-end products have a wide enough temperature range to allow a single product to be used all year round (instead of summer and winter grades) which has obvious logistical benefits and is important in environments with wide seasonal temperature variations. Consistent viscosity at extremes of temperature is essential to ensure adequate slumping within trackside applicator tanks to avoid pump cavitation and ensure consistent application on demand. Furthermore, it ensures consistent and stable beading from the applicator equipment.


Generally speaking, the further a lubricant remains detectable and effective from the point of application (“carry down”), the better. From a customer’s perspective this is a key performance criteria as better carry down reduces the number of trackside dispenser systems needed along with their associated maintenance and replenishment costs, and reduces the application rate of grease required. It must be noted that this characteristic is heavily influenced by factors such as track condition, vehicle axle loading and number of axles over a given period.


Adhesion in this context means the ability of the lubricant to stick to a wheel or track, not physical adhesion between rolling stock wheels and track. Cohesion refers to the ability of a lubricant to stick to itself. These are important as they relate to the amount of “splash-off” when a train initially picks up lubricant, and “fling-off” from the trains rotating wheels during the carry-down phase. Good cohesion also affects a lubricant’s elastic properties and helps minimise the amount of lubricant “squeezed” out of a contact patch under pressure, this particularly becomes a problem if the grease migrates to the top of the rail. Better Adhesion and Cohesion means more of the lubricant stays where it is needed leading to better performance, better carry down, less environmental contamination and less waste.


A key characteristic here is stability in storage both pre-use and in dispenser tanks to minimise oil separation across the full operational and storage temperature ranges. Although a degree of oil separation is normal and essential from a performance perspective, excessive oil bleed is a problem as the grease left behind can become too thick and cause issues with pumpability and blockages in the lubricator. 


Good EP and AW characteristics indicated by both 4 ball weld and scar testing are essential in curved rail grease applications. Axel loads can be anything up to 40 tonnes which creates enormous pressures at the wheel/rail interface, and the grease film needs to be strong enough to prevent the metal to metal contact which then leads to increased wear and reduces track and wheel life.


The lubricant’s ability to offer corrosion protection to the steel rails and wheels is essential, particularly in adverse and wet conditions.


A further desirable characteristic for flange lubricants is good resistance to water wash-off to ensure that the lubricant film is maintained in wet conditions over the claimed carry-down distances. It’s no use having great carry down characteristics if when it rains the grease is washed off and the rails and wheels are left unprotected.


Products should be designed to be compatible with as many other rail lubricant and friction modifier technologies as possible. On some networks this is safety critical due to the risk of product “build up” neutralising track circuits and therefore train detection. In addition, the ability to replace existing Flange Grease in dispenser equipment without cleaning out the old product is a distinct advantage.


Grease consistency is measured on a scale called the NLGI classification. For trackside rail curve lubricants, if the grease is too thick it can cause a problem with pumpability and cause clogging in the grease tank-pump inlet, outlets, pipes and GDU ports. If the grease is not thick enough it will not form stable beading on the GDU and will cause increased “splash-off” and “fling off”, meaning less of the grease gets to where it’ required in the contact interface between wheel and rail. A too thin grease can also increase the undesirable grease migrations to the top of the rail. Grease consistency has to match the application method, which is very different for trackside lubrication than it is for onboard lubrication.


The grease structure needs to be stable enough to withstand mechanical working without it breaking down and losing its consistency and other attributes.


The fact that rail curve lubrication is a ‘total loss’ system where all the lubricant enters the environment means “Eco Credentials” are becoming increasingly important for many users. For a grease to excel in this category, it should be readily biodegradable, non bio accumulative, have low aquatic toxicity and have a large proportion of its raw materials be from renewable sources. Accreditations such as the European Ecolabel ensure that a product meets very strict environmental criteria and contributes to a network’s broader sustainability initiatives.




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