There are various types of steel commonly used for spring applications, depending on the specific requirements of the application. Some of the common types of steel used for springs include:

1. High-Carbon Spring Steel: High-carbon spring steel, such as AISI 1070 or 1095, is known for its excellent strength and ability to withstand heavy loads and repeated stress. It has a high carbon content, typically ranging from 0.60% to 1.00%, which contributes to its spring properties and resilience.
2. Alloy Spring Steel: Alloy spring steels, such as AISI 6150 or 9260, are formulated with additional alloying elements to enhance specific properties. These alloys can offer improved strength, toughness, and fatigue resistance compared to high-carbon steels. Alloy spring steels are commonly used in demanding applications that require higher performance and durability.
3. Stainless Steel: Stainless steel springs, often made from alloys such as AISI 302 or 17-7 PH, offer excellent corrosion resistance and high tensile strength. They are particularly suitable for applications where exposure to moisture, chemicals, or corrosive environments is a concern, such as in marine or medical applications.
4. Music Wire: Music wire, also known as high-carbon steel wire or ASTM A228 wire, is a high-tensile, high-carbon steel wire often used for small to medium-sized springs. It has exceptional strength and is renowned for its ability to maintain its properties under repeated stress and tension.
5. Oil-Tempered Wire: Oil-tempered wire, also known as OTMB (Oil-Tempered Mechanical Spring Wire), is a type of steel wire that undergoes a specific heat treatment process involving oil quenching and tempering. This process enhances the wire's strength, durability, and resistance to deformation and fatigue. It is commonly used for heavy-duty springs and industrial applications.

The choice of steel type for a spring depends on factors such as the required strength, durability, corrosion resistance, temperature range, and other specific performance requirements for the application. It is crucial to select the appropriate steel type and consult relevant material specifications and industry standards to ensure the desired performance and longevity of the spring.