The main difference between steel and spring steel lies in their composition, properties, and intended use.

1. Composition: Steel is a broad term that encompasses a wide range of alloys primarily composed of iron and carbon. It can contain various other elements in varying proportions to achieve specific properties. On the other hand, spring steel refers to a specific type of steel that is specifically formulated for its excellent elasticity and resilience. Spring steel typically has a higher carbon content than regular steel to provide the desired spring-like properties.
2. Elasticity and Resilience: Spring steel is designed to have high elasticity and resilience, allowing it to withstand repeated bending or twisting without permanent deformation or breakage. Regular steel may not possess the same level of elasticity or resilience as spring steel, as it is not specifically engineered for those characteristics.
3. Applications: Steel has a broad range of applications across industries, including construction, automotive, machinery, and more. It is used for structural components, tools, machinery parts, and various other applications. Spring steel, as the name suggests, is primarily used in applications where its spring-like properties are essential. It is commonly utilized in the manufacturing of springs, such as those found in automotive suspensions, industrial machinery, locks, and other applications where elasticity and resilience are crucial.
4. Heat Treatment: Spring steel is often subjected to specific heat treatment processes to optimize its mechanical properties and enhance its spring-like characteristics. This heat treatment can involve techniques such as quenching and tempering to achieve the desired hardness, strength, and resilience. Regular steel may also undergo heat treatment but for different purposes based on its intended application.

In summary, while both steel and spring steel are composed of iron and carbon, the key difference lies in the purpose and properties of the materials. Spring steel is a specific type of steel designed for its elasticity and resilience, primarily used in spring applications. Regular steel refers to a broader category of alloys used in various applications that may not require the same level of elasticity and resilience as spring steel.