This Resource Centre provides general guidance only. Always follow the equipment manufacturer’s instructions, the product technical data sheet and your site’s safe system of work. Isolate stored energy before maintenance. For safety-critical, regulated or uncertain applications, ask a competent engineer or the product manufacturer to confirm the specification.
A grease is a formulated system of base oil, thickener and additives. Colour alone does not identify performance or compatibility.
Start with the specification
Find the lubricant designation in the machine manual, lubrication chart or component data. If it is unavailable, collect the operating details before selecting an alternative.
Base-oil viscosity
The base oil forms the lubricating film. Required viscosity depends mainly on component type, speed, load and operating temperature. A product that is too thin may not separate surfaces adequately; one that is too viscous can create heat and drag.
Thickener
The thickener gives grease its structure and affects water resistance, mechanical stability, temperature performance and compatibility. Greases with different thickeners may not mix safely, even if their stated consistency is similar.
Consistency
NLGI grade describes consistency, not quality or base-oil viscosity. Softer greases may suit centralised systems or cold conditions; firmer greases may stay in place more readily. Use the grade specified for the application and delivery method.
Additives and approvals
Depending on the application, you may need extreme-pressure or anti-wear performance, corrosion protection, electrical properties, low-noise behaviour, food-grade registration or compatibility with particular plastics and elastomers.
Before changing product
Ask:
- Are the old and new greases compatible?
- Can the old product be fully purged or removed?
- Will the change affect seals, automatic lubricators or central lines?
- Does the new product have the necessary approvals?
- Has the relubrication interval been reassessed?
Where compatibility is uncertain, treat the greases as incompatible and obtain manufacturer advice.
Need help sourcing the item?
Send the manufacturer, reference, photographs and operating details.