Abstract: This research is dedicated to design and manufacture the mechanical fuse shear pin, especially, that used in the rolling machine of the General Company for Copper and Mechanical Industries in Iraq. Finite element analysis that performed by ANSYS Software is used to accomplish the numerical part of this study. The maximum normal stress theory is selected as the failure criterion. A gray cast iron material is employed in shear pin preparing. To check shear pin’s specimens, a completed testing system is designed and manufactured. Consequently, detailed tables are presented to select a suitable geometry of shear pin’s notch for any value of torque requires by the rolling machine. Also, the effect of the notch angle, notch depth, notch tip radius, notch shape and the ultimate tensile strength on the value of the torque at the fracture is obtained and explained by tables, sketches and contours. A comparison between the numerical and experimental works is shown an acceptable result. The error between the ANSYS and the experimental data is not exceeding (4%).