All load lifting hooks shall be made of which material?

• A. Aluminum
• B. Stainless steel
• C. Alloy steel
• D. Carbon steel

Answer: (C)

When selecting material for load lifting hooks, the key requirement is a combination of high strength, toughness, and fatigue resistance, with the ability to be heat-treated to achieve the proper hardness and ductility. Alloy steel provides this balance: it can be heat-treated to attain high strength while maintaining toughness, and it resists fatigue under repeated dynamic loads that hooks experience during lifting. Stainless steel, while corrosion resistant, generally does not offer the same level of fatigue performance under heavy, repeated shocks and can be more expensive. Carbon steel is strong but lacks the improved toughness and fatigue resistance that alloying elements in alloy steel provide. Aluminum is not suitable due to insufficient strength for heavy lifting. So, alloy steel is the best choice for load lifting hooks.