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Abstract In bolted joint assemblies, accurate torque application is essential to achieving the correct preload, which is critical for joint integrity and long-term performance. The K-factor (or nut factor) is a key element in torque calculations as it directly influences the relationship between the applied torque and the resulting tension (preload) in the bolt. An incorrect K-factor can lead to inaccurate preload, resulting in either under-tightening or over-tightening. Under-tightening may cause insufficient clamping force, leading to joint loosening, leaks, or fatigue failure. Over-tightening, on the other hand, can overstress the bolt, damage the joint components, or crush the gasket, potentially leading to catastrophic joint failure. The K-factor is influenced by several factors, including lubrication, surface finish, bolt material, coatings, and the condition of the threads. Each of these factors affects the friction present between the threads and under the bolt head or nut, which in turn alters the amount of torque required to generate the desired preload. While the use of new studs is always recommended when assembling flange joints, this is often impractical due to time constraints or the unavailability of new hardware. Therefore, understanding the impact of reusing studs—particularly those with different coatings and lubrication—on the K-factor becomes critical for ensuring proper joint performance. This paper focuses on how the K-factor changes when reusing studs with different coatings. It examines the commonly used coatings such as PTFE (Polytetrafluoroethylene), Black Oxide, and Zinc-Nickel (Zn-Ni) plating on the K-factor when studs are subjected to multiple reuse cycles. These coatings are widely used in bolted joints to protect against corrosion, improve friction control, and enhance the longevity of the fasteners. However, after repeated use, the effectiveness of the coatings and their impact on friction—and thus the K-factor—can change significantly. Additionally, the paper explores the benefits of lubrication when reusing coated studs. Lubrication plays a crucial role in reducing friction between mating surfaces, which lowers the K-factor and leads to more predictable and consistent preload. The study evaluates how the use of lubrication interacts with different coatings to maintain consistent preload in reused studs. By comparing the K-factors for different coating and lubrication combinations over multiple cycles of reuse, this paper provides insights to the limitations of reusing bolts for maintaining joint integrity when new hardware is not available. These results are relevant for industries such as petrochemical, power generation, and heavy machinery, where flange joints are critical components of pressure vessels and piping systems.