Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1399684
6 | July - August 2021 | www . machinerylubrication.com outlets wanting you to purchase their product. It's important to note that the term "multipurpose" does not have a formalized definition, so this is largely marketing and a common term used to define a grease that may work in multiple applications. We think back to our consoli- dation task force that is sitting in a conference room pouring over lubricant technical data sheets and machine manuals to determine the best lubricant to use in their machine, and they come across a grease that is listed as multipurpose. is is viewed as a godsend as it falls in line with what we are hoping to do — find a lubricant that will perform well in multiple applications without sacrificing the health of the machine. Looking at the equipment manuals, all they recommend is to use an NLGI 2 Lithium grease, so surely this multipurpose grease will work fine. Unfortunately, without an industry standard, these greases can vary widely in their perfor- mance as well as their chemical and physical properties. "Multipurpose" has become such a normal descriptor for grease that it has further confounded the issue of over-consolidation. Looking through just three different lubricant manu- facturers' product catalogs yielded over a dozen products using the term "multipurpose" in the descrip- tion of the grease. When compared to each other, there were a variety of different thickeners used, a wide range of base oils and varying addi- tive loads. Many were lithium or lithium complex thickened greases, but some were aluminum complex and even polyurea. The base oil viscosity ranged from the low end of an ISO 100 all the way up to an ISO 460. Some had solid addi- tives such as molybdenum, while others were more formulated to resist water-washing. So, selecting a grease based solely on a marketing term could have disastrous effects on our equipment. LUBRICANT SELECTION New NLGI Certifications Eliminate Confusion The NLGI (National Lubricating Grease Institute) has seen the need for updated grease specifications and are currently building these specifications, complete with performance testing criteria. While the traditional wheel bearing and chasis certifications will persist, new certifica- tions will be created in order to further segment greases, breaking down the "one-size-fits-all" approach. High-Performance Multiuse Grease (HPM) is the first of these new certifications. It serves as a core specification and has additional performance tags to further designate a specific grease application. These tags include water resistance (HPM+WR), salt-water corrosion resistance (HPM+CR), high load (HPM+HL), and low temperature (HPM+LT). There is no limit to the tags a grease may have, so it is possible for a formulation to achieve multiple tags based upon its performance in testing. This is certainly a great step forward and helps to ensure that the lubricant selected is correct for the application, bringing grease certifications into the modern age. For more information on these certifications, specifications, and testing you can visit the NLGI website here: https://www.nlgi.org/about-us/high-performance-multiuse-grease/