(a) List the four classifications of steels. (b) For each, briefly describe the properties and typical applications.

Answer: The four main classifications of steel are carbon steel, alloy steel, stainless steel, and tool steel. 1. Carbon steel contains mainly iron and carbon, with good strength and durability but is more prone to rust and corrosion. It is used in structural applications, railway tracks, and cutting tools, depending on the carbon content (low, medium, or high carbon steel). 2. Alloy steel contains a combination of alloying elements and offers greater strength, toughness, and resistance to wear, heat, and corrosion. It is commonly used in the automotive, aerospace, and energy industries for components such as gears, aircraft parts, and high-strength pipelines. 3. Stainless steel contains at least 10.5% chromium, making it highly resistant to rust and corrosion. It is used in food and beverage processing equipment, chemical processing equipment, and architectural applications. 4. Tool steel is a specialized type of steel with high hardness and wear resistance, used for cutting, forming, and shaping tools and dies, punches, and wear components.