The effect of steel balls based on different standards on the anti-wear properties of lubricants

Purpose ‐ Through practical tests, it has been found that steel balls based on different standards could affect tribological performances of the same lubricant, but unfortunately, past researches in the field have been quite inadequate. The aim of this paper, therefore, is conscientiously to study the problem. Design/methodology/approach ‐ The anti-wear properties of four kinds of lubricants were evaluated by four-ball tester using two kinds of steel balls based on different standards. The reason for different anti-wear properties of the same lubricant was also discussed using hardness tester and scanning electron microscope with an energy dispersive spectrometer (SEM/EDS). Findings ‐ It was found that steel balls based on different standards could affect the tribological results for the same lubricant. The reason could lie in the surface chemical composition, surface roughness and hardness of steel balls which originated from the subtle difference of different standards. Originality/value ‐ The paper shows that, as far as evaluating anti-wear properties is concerned, steel ball based on AISI Standard Steel No. E-52100 is a better choice than that based on Chinese standard GB 308.