Bearing failure is one of the most common — and most avoidable — causes of unplanned machinery downtime. In a large number of cases, the root cause isn't a bad bearing at all. It's the wrong grease, applied in the wrong quantity, at the wrong interval. If you're sourcing grease for factory machinery, understanding the basics can save you from repeat failures and unnecessary maintenance costs.
What Does the NLGI Grade Actually Mean?
NLGI (National Lubricating Grease Institute) grades measure grease consistency — essentially how thick or firm it is. This isn't a quality rating; it's a functional specification that must match your equipment's requirements.
- NLGI Grade 1 - Softer consistency, used in centralized lubrication systems where grease needs to flow through pipes.
- NLGI Grade 2 - The most common industrial grade, suited for general-purpose bearings, motors, and standard machinery operating at normal temperatures.
- NLGI Grade 3 - Firmer consistency, used in high-temperature or heavy-load applications where the grease must resist slumping or being pushed out of the bearing under pressure.
Matching Grease to Application
Beyond NLGI grade, the base oil and thickener type matter just as much:
- Lithium-based grease — Good all-purpose choice, water-resistant, suitable for most industrial bearings and general machinery.
- Calcium-based grease — Better water resistance, often used in wet environments but with lower temperature tolerance.
- Complex thickener greases — Designed for higher temperature ranges and extended service intervals in demanding industrial applications.
Using a grease designed for one application in another — for example, a low-temperature grease in a high-heat furnace bearing — leads to the grease breaking down, oxidizing, or leaking out, leaving the bearing under-lubricated.
Common Mistakes That Cause Bearing Failure
- Over-greasing — Excess grease generates heat through churning and can cause seal damage, leading to contamination ingress.
- Under-greasing — Insufficient lubrication leads to metal-to-metal contact and rapid wear.
- Mixing incompatible greases — Different thickener types can react and break down when mixed, reducing lubrication effectiveness.
- Ignoring temperature ratings — Using a standard grease in high-temperature applications causes it to oxidize and harden faster than expected.
How Often Should Industrial Grease Be Replenished?
Re-greasing intervals depend on operating speed, load, temperature, and environment. As a general rule, high-speed or high-temperature bearings need more frequent attention, while slow-moving, lightly loaded equipment can go longer between applications. Always refer to your equipment manufacturer's lubrication schedule as the primary guide.
Sourcing Industrial Grease in Bulk
For factories and manufacturing units, sourcing grease in bulk drums rather than small containers reduces cost per kilogram and ensures consistent supply. Aggarwal Lubricants India is a trusted industrial grease supplier in India, supplying genuine Servo and HP grease in NLGI Grade 2 and Grade 3 formulations. Based in Rohini, Delhi, we serve manufacturing plants and industrial units with wholesale pricing on bulk drums and barrels, along with pan-India delivery.
genuine Servo and HP greaseFrequently Asked Questions
Can I mix different brands of industrial grease?
It's not recommended unless both greases use the same thickener type. Mixing incompatible thickeners can cause the grease to soften, harden, or separate, reducing lubrication performance.
What NLGI grade is best for electric motor bearings?
NLGI Grade 2 lithium-based grease is commonly used for electric motor bearings, though always check the motor manufacturer's specification.
Do you supply industrial grease in bulk for factories?
Yes, we supply industrial grease in bulk drums and barrels at wholesale pricing, with pan-India delivery for manufacturing plants and industrial units.
How do I know if my machinery needs Grade 2 or Grade 3 grease?
This depends on operating temperature and load — our team can help match the right grade based on your equipment specifications. Contact us for guidance before ordering.