Lubricating grease formulation analysis: thickener, base oil and additives
Start with the formulation of unused grease
Before interpreting a steel dust check in grease, distinguish the supplied formulation from material acquired during service: we can investigate supported thickener, base-oil and additive chemistry in new grease. We consider only unused new grease from overseas after review; used grease counts as waste that we cannot receive from overseas. For the wear-monitoring question itself, see steel dust and wear metal in grease.
The base oil and thickener are separate components
A grease holds a base-oil phase within a thickener structure and adds smaller ingredients for its intended operating conditions. Base oils can include mineral oils, synthetic hydrocarbons, esters or silicone oils, which represent different chemical families rather than interchangeable descriptions of one liquid. GC-MS can support suitable accessible oil components, while the overall base-oil conclusion may remain at chemical-family level where a complex distribution cannot be resolved more narrowly.
Common thickener systems include lithium, lithium-complex, calcium and aluminum soaps, alongside bentonite and polyurea systems. A soap-thickened grease combines metal-containing and organic chemistry, so a metal result alone cannot establish the complete thickener structure. ICP-MS can support relevant metal-element findings, which we interpret alongside the organic ingredients and other possible mineral contributions.
Look beyond the main thickener
Grease additives can include antioxidants, extreme-pressure and antiwear ingredients, rust inhibitors and solid lubricants such as molybdenum disulfide or graphite. Some metal-containing ingredients are intentional formulation components, so metal in fresh grease is not automatically evidence of wear or contamination. An elemental molybdenum finding, for example, is not sufficient by itself to distinguish a solid lubricant from another molybdenum-containing additive.
LC-MS/MS and GC-MS can support suitable accessible organic-additive evidence, with specific identities assigned where reference spectra or standards are available and the evidence supports the distinction. We can estimate supported component proportions on the received-grease basis, with unresolved fractions stated rather than converted into an exact mixing sheet. The same thickener-family label can accompany different base oils and additive balances, making a full formulation comparison more useful than the label alone.
Compare new products with new products
For example, a manufacturer who wants to check a supplier change can compare two unused greases for thickener family, oil-family evidence and retained additive pattern. If an unused delivery appears to contain unexpected metal, describe that observation and compare it with an unused reference instead of assuming that a metal signal proves steel particles. Composition analysis does not provide dropping point, worked penetration or bearing-life results, and a chemical resemblance does not guarantee equal lubrication performance. Our industrial-fluid guide covers cleaners, metalworking fluids and grease together; this page isolates the grease formulation.
Declare the actual fresh product
Unused semi-solid grease is subject to declaration and SDS review, and grease containing additives outside the existing chemical inventory is reviewed case by case after declaration. Lubricating oils and other non-water-based liquid oils are not received from overseas as supplied, so do not substitute a liquid oil sample for the declared grease.
How to start
We review overseas industrial samples before acceptance. Use our industrial analysis page and sample-shipping guide to prepare your declaration. Our reports are research-grade analytical reports from a laboratory that is not accredited. They cannot be used for product registration or legal proceedings.
FAQ
Does lithium prove a specific thickener system?
Lithium supports an elemental finding, but distinguishing a lithium soap from a lithium-complex system needs interpretation of the accompanying chemistry.
Is metal in new grease necessarily contamination?
Metal in new grease can belong to the thickener, an additive or a mineral ingredient, so unexpected-metal questions need a formulation context and a suitable unused reference.
Can similar formulation results predict bearing life?
Similar supported grease chemistry does not provide bearing-life or consistency results, which depend on physical structure and operating conditions as well as ingredients.
Can I send grease recovered from a bearing?
Used grease recovered from a bearing counts as waste and cannot be received from overseas; declare unused new grease if the question concerns the supplied formulation.