What material is commonly used for coolant hoses?

Rubber is the material commonly used for coolant hoses due to its excellent flexibility, resilience, and ability to withstand high temperatures associated with automotive cooling systems. This flexibility is essential as coolant hoses must navigate around various engine components and allow for thermal expansion and movement. Additionally, rubber has good chemical resistance against the coolant and other fluids it may come into contact with, ensuring durability and preventing leaks. Its ability to seal effectively also contributes to maintaining the integrity of the cooling system, which is critical for engine performance.

Other materials like steel, plastic, and glass do not offer the same combination of properties needed for coolant hoses. Steel, while strong, is not flexible and would be prone to corrosion. Plastic may not withstand the high temperatures as efficiently, making it less reliable in extreme conditions. Glass could break easily under stress or impact, making it unsuitable for the flexible and dynamic environment of an engine compartment.