This article investigates the interference fit requirements for customized dual-fit fasteners in a linear guide rail mounting application. The shaft support mount used in this study is designed to support linear guide rails and is fixed to a surface using customized dual-fit fasteners. The interference fit between the two parts of fasteners is calculated to determine the necessary friction to hold both parts attached. This study aims to optimize the frictional force in the shaft support mount attachment and investigates the effects of the fastener diameter, material, and surface roughness on the interference fit. The results of this study show that the interference fit between the two parts of the fasteners significantly affects the frictional force required to hold the shaft support mount attached to the surface. The findings of this research can be used to improve the design of linear guide rail mounting systems and provide guidance for engineers and designers when selecting customized dual-fit fasteners for similar applications.