Tribological considerations of threaded fastener friction and the importance of lubrication

The torque-tension relationship of threaded fasteners affects almost all engineering disciplines. Tribological processes at fastener interfaces manifest as the system's friction coefficient. Lubrication-related influences are usually described empirically using K or μ. The drive towards lightweight fastener materials in engineering systems and lubricants with reduced environmental impact is challenging existing knowledge and industrial practice in a range of applications, many safety critical. More comprehensive understanding is needed to achieve repeatable friction during assembly and re-assembly, resistance to loosening and fretting during operation, and effective anti-seize for disassembly with a growing range of materials and lubricants. The lubricants considered showed three predominant lubrication mechanisms: plastic deformation of metal powders; burnishing/alignment of molybdenum disulphide, MoS2; and adhering/embedding of non-metal particles. Multivariate analysis identified key sensitivities for these mechanisms. Assembly generated changes at fastener surfaces and in the lubricating materials. Re-assembly exhibited significant reductions in friction.

URI

http://hdl.handle.net/10454/19774

Version

Accepted manuscript

Citation

Dyson CJ, Hopkins WA, Aljeran DA et al (2024) Tribological considerations of threaded fastener friction and the importance of lubrication. Tribology International. 191: 109162.

Link to Version of Record

https://doi.org/10.1016/j.triboint.2023.109162

Type

Article