This document discusses the frequency comparison and optimization of crankshafts made from forged steel and ductile cast iron using modal analysis to assess their natural frequencies and optimize weight. The study finds that ductile cast iron has natural frequencies ranging from 890.735 Hz to 2623.305 Hz, while forged steel ranges from 931.808 Hz to 2741.032 Hz, with weight reductions of 15% and 14% respectively. The results indicate the potential for improved crankshaft performance and efficiency in engine design.