Springs are manufactured with different materials and finishes based on factors such as application, project requirements, and operating environments. Spring quality is crucial, and material or finish can have an impact on performance.
With so many materials on the market, here is what you need to know about choosing the best spring materials for your device or application.
Common Spring Materials
Springs are most commonly made of steel alloys because of their cost, availability and durability. The most common alloy types include music wire, chrome silicon, stainless steel and oil-tempered wire. Learn more about some common spring materials.
- Hard-drawn wire: Hard-drawn wire is often considered the most economical steel wire available. It is sturdy, versatile and easy to use. While hard-drawn wire will not work well in temperatures beyond 250°F, it performs well in most other working conditions. Hard-drawn wire would not typically be recommended for applications that require a long life, such as medical devices.
- Music wire: Music wire is durable and works well in various applications. Music wire is used in many heavy-duty industries such as construction and automotive repair, where durability is an essential factor. These springs are a good choice because they can handle heavy loads while retaining their build and form.
- Oil-tempered wire: Oil-tempered wire is ideal for applications that require heavy lifting consistently. It is an excellent choice for farm equipment and automotive machinery, partly because of its large diameter.
Springs made from chrome silicon wire are sturdy and have a high degree of malleable strength. Chrome silicon is a good choice for applications that have high-impact requirements or need to perform high-pressure tasks repeatedly. This spring material works well in most work environments but can break down in extreme temperatures.
Inconel alloys are an excellent choice in extreme environments, particularly high-temperature atmospheres. This material is common in the aerospace and nuclear energy industries.
- Grade 301 stainless steel: Many standard spring charts, including our constant force spring charts, are based on 301 stainless steel. It is corrosion resistant in many environments.
- Grade 302 stainless steel: Many stock commercial springs use 302 stainless steel. This material has a higher resistance to corrosion than 301 because it contains more nickel. 302 stainless steel can withstand high temperatures, up to 550°F. Generally, stainless steel is good for medical applications.
This is not a comprehensive list of all spring materials available. What material you need should depend on your project requirements.
What Factors Are Important in Selecting Spring Materials?
- Corrosion resistance: Corrosion can have a massive impact on the durability, performance, and longevity of the spring. Corrosion often manifests itself in the form of rust on springs made from steel, which impacts the strength of the metal. Spring failure is common in springs affected by corrosion. Copper-based alloys and stainless steel are good choices because of their corrosion resistance.
- Environmental factors: Design engineers should account for environmental factors that can impact the spring’s performance. Factors to consider include humidity levels, average operating temperatures, and operating environment. Designers should also assess the prevalence of vibrations in the working setting, as vibrations can damage springs. Operators may need to adjust the spring material, size, or position based on these various factors.
- Affordability: Hard-drawn wires are affordable but may not be appropriate for high-pressure operating environments. Choosing a high-quality, durable material is an investment that will likely pay off in the future.
Other factors to consider include elastic deformation, tensile strength, and electric conductivity. Designers should consider all of these factors when choosing the best material and finish for their application.
Need help choosing the right material for your spring? John Evans’ Sons has a design engineering team that can help you with important considerations such as material.