Akademik Veri Yönetim Sistemi
Reports in Mechanical Engineering, cilt.6, sa.1, ss.1-11, 2025 (Scopus)
In this study, a geometric approach is proposed to estimate the surface roughness of holes in the drilling process. This recommended model can be used to predict the hole surface quality based on the tip angle of the twist drill bit. This proposed, original approach has not been previously reported in the literature. The proposed theoretical approach aligns well with the experimental results. Depending on the results, surface roughness of hole calculated by using the new analytical method were quite compatible with the experiments. Although the point angle varies depending on the hardness of the material to be drilled, for steel workpieces, the standard point angle of 118° is the most common. However, according to the relevant standard, the tolerance of the point angle of 118° for twist drills up to 12 mm diameter can be ±5°. This means that for a 118°-point angle drill bit, the point angle can be between 113° and 123°. In order to support the proposed theory, experiments were carried out with drill bits with point angles of 113°-123°. In addition, the effects of these angular tolerances on hole surface roughness, hole hardness and circularity were also revealed. In this study, the effects of drilling parameters such as different point angles, presence and absence of cutting fluid on surface roughness, Vickers hardness and circularity of holes were investigated in drilling.