This presentation discusses the design of cast iron pulleys. It begins by introducing cast iron pulleys and their typical construction with a rim held by arms or spokes connected to a central boss. The presentation notes that cast iron pulleys are made of grey cast iron and the rim and arms are typically steel. It then discusses features like crowning, which keeps the belt centered, and split pulleys, which allow mounting on an existing shaft. The presentation concludes by providing formulas for calculating torque transmission and determining the required elliptical cross-section of arms, using an example of a 500mm pulley transmitting 10kW of power.