ORIGINAL RESEARCH ARTICLE Failure Analysis on the Wheel Bolt of Light-Duty Vehicle Through Metallurgical Investigation Dilinesaw Bogale . Tesfaye Tamiru . Abraham Debebe . Haileyesus Hatano . Ewnetu Getu Submitted: 7 July 2023 / Accepted: 17 July 2023 / Published online: 3 August 2023 Ó ASM International 2023 Abstract This paper contributes to know the root causes of wheel bolt failure using experimental methods by pro- viding appropriate solutions concerning repair strategies and the mitigation of future failure for durable vehicle operation. The investigation was carried out on a damaged and new specimen for comparison purposes with the standard specification of the bolt. The analysis was con- ducted through fracture surface examination of visual observation, chemical composition, metallographic analy- sis, and mechanical hardness test. The experimental results revealed that the fracture surface of the damaged bolt showed fatigue beach mark characteristics that uninten- tionally can occur due to fatigue, and the microstructural examination exhibited a more amount of dark structure on the damaged specimen because of the increased carbon content in the bolt. Finally, it was concluded that the typ- ical features of overloading and fatigue mechanism observed at the bolts are assessed as the likely probable root cause of failure in wheel bolts. Keywords Wheel bolt Á Fracture Á Overloading Á Light-duty vehicles Abbreviation FDRE Federal Democratic Republic of Ethiopia Introduction A few centuries ago, threaded fasteners were developed and used in engineering applications to secure components together [1]. The primary reason to use bolts instead of welding or rivets is that the ties are simple and straight- forward, making them appropriate for use in any form of machinery [2], to provide continuity of structures and transfer of loads from one member to another. Bolts, screws, and studs are among the most prevalent threaded fasteners used in the industry to secure two or more mechanical parts together if part removal or replacement is required [3–5]. Besides that, they are also commonly used in a variety of automotive and structural systems to assemble and disassemble machines for maintenance and repair [6]. In most circumstances, bolted connections are observed as unpredictable and a common source of failure in service [7]. In any machinery, bolt failure is unwanted as it is an important tool that gets burdensome when subjected to failure and commonly occurs at contact interface other than within the bulk of the system [8]. Typically, these bolts and wheel bolts are used in the vehicle industry to secure various automobile components together. They are anticipated to be the most vulnerable element for failure phenomena due to friction at the interface and varying service loading factors. But even so, what makes wheel bolt failure even worse is that it occurs catastrophically D. Bogale (&) Á H. Hatano Faculty of Mechanical Engineering, Arba Minch Institute of Technology, Arba Minch University, P.O. Box 21, Arbaminch, Ethiopia e-mail: bogaledilinesaw@gmail.com T. Tamiru Mechanical Engineering, College of Engineering, Wolayta Sodo University, Sodo, Ethiopia A. Debebe Department of Mechanical Engineering, Addis Ababa Science and Technology University (AASTU), Addis Ababa, Ethiopia E. Getu Renewable Energy Technology Research Center, Arba Minch Institute of Technology, Arba Minch University, Arbaminch, Ethiopia 123 J Fail. Anal. and Preven. (2023) 23:1732–1740 https://doi.org/10.1007/s11668-023-01718-4