The consistency of lubricating grease is crucial as it determines its suitability for specific applications, particularly its ability to resist leakage and form stable lubricant channels within bearings. These channels act as reservoirs for bearing functionality throughout the machine’s operational lifespan.
The consistency of grease depends on the type and amount of thickener used, as well as the viscosity of its base oil. It refers to the grease’s ability to resist deformation under force, measured by penetration, which can be influenced by handling or usage.
The National Lubricating Grease Institute classifies grease consistency. This blog explores how grease stiffness is measured and its applications across NLGI grades.
NLGI in a Nutshell
The National Lubricating Grease Institute is a non-profit organization founded in 1933, whose mission is to disseminate relevant information for grease manufacturing and usage. NLGI serves grease manufacturers and end-users, aiming to strengthen its association through continuous service delivery.
Today, NLGI comprises over 200 member companies across 31 countries, including grease manufacturers, additive suppliers, distributors, original equipment manufacturers, end users, and educators.
Membership is company-based and includes equipment, supplies, and services suppliers, along with research, educational groups, and technical-focused companies.
NLGI Classification of Grease Stiffness
Softer greases are preferred for easier applications and are especially useful for bearings with seals and shields. Moreover, a soft to medium consistency allows the even distribution of grease inside the bearing.
On the other hand, stiffer greases find use in bearings, one in applications where a grease’s adherence inside a bearing is important, such as in open bearings and bearings subject to extreme vibrations, moisture, and dust.
Applications of Different NLGI Grades
Softer Semi-Flowing Greases (NLGI 000 and 00)
NLGI Grades 000-0 greases are fluid to semifluid, less viscous options suitable for enclosed and centralized applications. It is used for open gear systems where greases are sprayed or used as a bath.
NLGI 000: Liquid-like grease with minimal thickener, suitable for sliding surfaces, guides, and centralized lubrication systems with low-temperature pumpability.
NLGI 00: Like NLGI 000, used for open gears, spur gears, and bearings in both standard and severe conditions.
NLGI 0: Semifluid grease with good flow and low temperature pumpability, ideal for roller bearings, chains, and enclosed gearboxes.
NLGI 1: Soft, tomato-paste-like consistency, suitable for bearings and electric drive applications.
NLGI 2: Peanut-butter-like consistency, widely used in automotive and industrial applications, including bearings and flexible couplings. Some grease suppliers use descriptions like NLGI Number 1.5, indicating a consistency between NLGI Numbers 1 and 2.
Stiffer Greases (NLGI 3 or higher)
NLGI 3: Semi-solid grease for automotive, industrial, and marine applications, offering good sealing properties.
NLGI 4: Moderately stiff grease for water pumps and high-speed, lightly loaded applications.
NLGI 5: Stiff grease with low oil separation, used in overhead conductors and high-speed applications.
NLGI 6: Very stiff grease, uncommon, used in pillow-block lubrication and high-speed applications requiring minimal oil separation.
Fluid Solutions: Your Trusted Grease Supplier in the Philippines
Fluid Solutions is a leading manufacturer of metalworking fluids and industrial lubrication solutions. We offer a wide range of greases—from multipurpose greases to extreme pressure greases—with various NLGI grades.
We empower businesses to protect machinery and optimize performance with our expertise and commitment to quality.
The Fluid Solutions team provides lubrication solutions that boost productivity and extend component life. Our commitment includes delivering goods and services promptly, conducting business with honesty and transparency, responding to client communications within 24 hours, and offering excellent pre- and post-sale services.
Looking for a trusted and reliable grease supplier in the Philippines? Contact us at (02) 8370 5928 / (0917) 894 9156 or drop by our inbox at [email protected] for personalized guidance on selecting the right lubricants for your needs. You can also visit our Facebook or LinkedIn page to learn more about our products and services.
