Since many products rely on the durability of their spring components, it is crucial to select high-quality springs that will not fail prematurely. Untimely spring malfunction can be the result of several factors, which include poor design, the use of low-quality materials, or an inferior manufacturing method. Although a spring may seem like a minor component within a larger device, functional failure of the spring could result in device malfunction. This is why the quality of the materials being used to produce a spring and the manufacturing process should be taken into consideration before making a purchase.
Springs are generally made of hardened steel. The spring manufacturer has the option of using either pre-hardened steel before forming the spring, or they can also harden the spring after the formation process. The most commonly used spring steels are music wire, stainless steel, chrome silicon, oil tempered wire, and chrome vanadium. The different materials are ideal for a number of different conditions.
Music Wire is used for applications that demand a great deal of strength and results in an overall high-quality spring.
Stainless steel creates a product that functions well in moist environments since it will not rust.
Chrome Silicon will allow for use in higher temperatures and is a higher strength and quality version of oil tempered wire.
Oil Tempered Wire is used for many common applications but will not usually result in the strongest or most uniform product.
Chrome Vanadium has a similar quality structure to chrome silicone and is ideal for high temperatures.
The Manufacturing process
Step One – The manufacturing process starts with coiling the spring. This can be done with either cold or heated wire. Cold winding starts with a wire that is at room temperature and involves winding the wire around a shaft. The process of hot winding is used for thicker wire or bar stock. The metal is heated beforehand to increase wire flexibility and then the steel is coiled around a shaft while it is still extremely hot. After it has been coiled, it is immediately taken off of the shaft and dipped into oil so that it can cool and harden at a rapid rate.
Step Two – Once this step is complete, the steel needs to completely harden. The coiling process causes stress in the wire, which is alleviated by heat treatment. The spring is heated in an oven for a specific amount of time at a set temperature and then placed aside to cool slowly.
Step Three – The following step is called shot peening and using a machine to strengthen the steel to prevent metal fatigue, which could cause cracking during its use.
Step Four – The next step is called setting. It sets the spring to function correctly and remain stable at a certain length. During the process, it is completely compressed, usually multiple times, so that all the coils are completely pressed up against their bordering coils.
Step Five – The final step in the creation of the spring is usually coating. This is done to prevent corrosion, and the whole surface of the spring is coated with liquid rubber or plated with another metal such as chromium or zinc.