Understanding Dry Lubricants

A dry lubricant, commonly known as a solid film or dry film lubricant, uses a dry coating to reduce friction between two surfaces. 

This means that this type of lubrication does not rely on a fluid or oil to provide the performance. This is a key benefit in harsh environments where traditional oils and greases may not be suitable.

Some common types of dry lubricants to consider are; Graphite, Molybdenum disulphide (MoS2/Moly) and PTFE.

They offer effective lubricating properties at high and low temperatures for unique applications. Where wet film lubricants may freeze, carbonise or degrade.

When to use a dry lubricant?

Dry lubricants are typically used when wet lubricants are not suitable for use and include applications where the lubricant may encounter:

• Extreme high and low temperatures
• High loads and contact pressures
• Other chemicals
• Dusty or dirty environments

This makes them ideal for high heat operations such as those found in glass manufacturing and metalworking.

Dry lubricants are also vital for several unique applications such as locks, plain and anti-friction bearings, slides, chains, actuators and mechanisms where a typical liquid lubricant might interfere with the metal parts or inhibit operation.

Can you use a dry lubricant for metal on metal?

For metal-on-metal applications where frequent friction and tension between metal parts is required, a dry lubricant is a good option.

A dry lubricant can offer low friction, anti-wear lubrication with a clean and dry protective layer.

Dry lubricants are especially useful in metal-on-metal applications that require a high or low temperature durability characteristic.

What are the pros and cons of dry lubricants?

As illustrated above, some of the pros of dry lubricants include their high heat resistance and non-liquid/dry applied film.

Some pros include:

• Low coefficient of friction film provides outstanding protection against wear
• Wide operating temperature range of -200°C to +550°C
• Does not attract dirt and dust
• Touch dry in under 1 minute allows components to be put back into service quickly

These qualities mean that dry lubricants are versatile solutions in applications where ‘wet’ film lubricants cannot be tolerated.

Some cons include:

• Specific applications and use cases
• Can be difficult to apply to lubrication systems
• The service life of dry lubricants is limited
• Poor self-heal properties – less effective when the film is broken

How does dry lubrication reduce friction?

Dry lubricants reduce friction between moving surfaces by forming a thin, solid film on the surface of the material(s) and allowing surfaces to slide with minimal resistance.

Dry Moly and Dry Graphite contain solid lubricants which form lamellar structures – the weak bonds between the layers are what allows the layers to easily slide over each other.

Dry lubricant’s containing fluorocarbons, like Dry PTFE are uniquely capable of resisting attack from another chemical structures, as well as having extraordinary bond strength.

DRY PTFE contains the Fluorocarbon PTFE, which has a molecular structure consisting of carbon atoms bonded to fluorine atoms, creating strong, stable bonds. 

This type of dry lubricant is therefore capable of resisting attack from other chemical structures, provide enhanced surface adhesion, minimise stick-slip, and reduce the coefficient of friction.

What are dry film lubricants used for?

Considerations when choosing a dry lubrication

As highlighted throughout this guide, dry lubricants are unique and useful lubrication solutions and an impressive advancement in lubrication technology.

They offer incredible thermal resistance in extreme applications and provide lubrication for uses that previously had no viable alternative solution.

Though they are useful, they come with some considerations and will only be successful when utilised in the right applications and conditions.

When looking to utilise a dry lubricant solution it is vital that you understand the solutions and can use these solutions effectively.

Speaking to an expert is vital for understanding dry lubricants further. To learn more about our leading range of dry lubrication options, get in touch with our expert team.

By speaking to an advisor, you’ll gain access to the full 85+ years of knowledge from Molyslip and be able to fully maximise your production.