Spring Manufacturing Explained: Processes, Materials & Applications

Springs are mechanical devices that deform under external pressure and return to their original shape when the pressure is removed. When the spring returns to its normal form, the energy used to deform it is stored and can be recovered. In custom spring manufacturing, precision and consistency are crucial. At Custiv, we leverage advanced [CNC machining techniques] (link) to deliver high-quality springs tailored to your design and performance requirements.

Spring manufacturing companies perform processes such as coiling, twisting, or bending spring wires into specific shapes using mechanical spring machinery. Spring manufacturing is a specialized mechanical process that requires thorough technical understanding. Types of Springs Various kinds of custom springs are manufactured at spring manufacturing companies. The selection depends on the force or torque. Some major spring types are:

● Compression springs: They are helically coiled wires designed to provide an opposing force when compressed.

● Extension springs: They are helically coiled wires designed to provide an opposing force when stretched.

● Torsion springs: These are flat spiral coils used to resist or apply torque loads.

● Constant force springs: They resemble a roll of tape as they are tightly wound bands of steel where spring rebounds with a constant force; it is also found in wind-up toys and similar devices.

● Belleville springs: These are used for pre-tensioning purposes, such as in fasteners, bolts, and disc springs resembling tapered discs.

● Drawbar springs: These are types of extension springs incorporated between two loops of wire. These springs are toughened coils of metal that help things return to a particular position.

● Volute springs: These are also known as conical springs, where the compression spring is in the form of a cone. The coils of the spring overlap and are guided radially by each other during compression.

● Garter springs: Coiled steel springs connected with each end to form a circle. Their primary function is to maintain lip seal pressure on shafts.

● Flat springs: They are flat strips of material that store and release energy when deflated by an external load. They are made from carbon steel or stainless steel. They are ideally used for applications where space is limited or where the spring is used as part of the mounting assembly.

● Air springs: They are vehicle suspensions powered by an electric or engine-driven air pump or compressor. These are used for providing shock absorption actuation and vibration.

Spring manufacturing companies employ several procedures for creating steel-alloy coiled springs, such as the following. • Coiling a. Cold winding: Here, spring manufacturing companies singularly wind a wire around a mandrel or an arbour, with the help of a specialized lathe, spring-winding machine, an electrically controlled drill with the mandrel set in a chuck, or the manual-cranking winding machine. As the lead screw, a guiding principle should align the wire onto the required pitch every time it wraps around the mandrel.

Next, the wire is pushed forward onto a support block towards a grooved block, which bends the wire. The support block and the spring’s head can now move relative to one another in five primary directions to control the formed spring's pitch and diameter. The ends can be bent into hooks, loops, or even straight sections once coiled for torsion and extension springs.

b. Hot winding: Bar stock or thick wire can be wrapped onto springs if bar stock is heated at a higher temperature to make it more flexible. Afterwards, the professionals at spring manufacturing companies coil up the standard coiling machinery to three steel bars with 75mm each. Reportedly, custom springs have been made of 150 mm-thick bars too. The steel gets coiled around the mandrel while still red-hot. Then, it is removed from the coiling machine and soaked into the oil to cool quickly and entirely for hardening. The spring is too brittle to act as a string; however, it later subsides during tampering.

Hardening ● Heat treating: Most spring manufacturing companies use heat treating to develop springs. Steel is stressed during the coiling process, whether cold or hot. The spring must be heat-treated to relieve this stress and maintain the steel's inherent toughness. It is heated in an oven, held at the correct temperature for a specific time, and then cooled slowly.

Finishing ● Grinding: If the designs appear to have flat ends to the experts working in the spring manufacturing companies, then the spring ends are grounded during this point of the entire custom spring manufacturing process. The spring is positioned in a zig-zag pattern, and it is held against a revolving abrasive wheel until the required flatness is reached. A fluid (oil-based substance or water) is ideal for cooling the spring, transporting particles, and lubricating grinding wheels during the grinding process.

● Shot peening: The shot peening process hardens steel over time, allowing it to withstand metal fatigue and fracture. Spring manufacturing companies commonly use this method to manufacture custom springs. The spring's entire surface is hammered smooth, and a bombardment of small steel balls compresses the steel just beneath the surface. ● Setting: The spring is completely compressed, ensuring that all coils contact and the correct length and pitch are maintained indefinitely. Some custom spring manufacturing companies engage in this activity regularly. ● Coating: To prevent any corrosion, experts in spring manufacturing companies paint the entire spring's surface, immersed in liquid rubber, plated with another alloy like chromium or zinc.

● Packaging: In spring manufacturing companies, springs can be packaged in bulk in plastic bags or boxes in any quantity. However, some spring manufacturing establishments use newer methods to keep springs from tangling or damage, such as individually packaging – strung on rods or wires, sealed in tubes, and secured with adhesive paper. Know more about the making of spring in spring manufacturing companies, visit us at Custiv!

Custom spring manufacturing uses steel alloys like low-alloy steel, cold-formed steel, oil tempered, Bainitic hardened steel, stainless steel, copper, and aluminium steel.

Low-alloy steel: It is a type of mixture containing steel and several other metals possessing properties required to prevent corrosion.

Cold-formed steel: These are made from structural quality sheet steel formed into C-sections and other shapes by roll composing the steel through a series of dies.

Oil tempered: The wire is heated at extreme temperatures and then cooled with oil to strengthen it without making it brittle.

Bainitic hardened steel: Bainitic commonly consists of cementite and dislocation-rich ferrite. It is used when crafting strengthened/fortified material with fatigue resistance—primarily used in railway transport for high strength and wear-resistant rails.

Copper and aluminium steel: They are mainly used as an electrical conductor in electrical cables due to their low resistance and excellent conductivity.

Custom springs are essential across multiple industries, including:

• Automotive: Suspension, brakes, and clutches. • Aerospace: Lightweight yet strong components for actuation systems. • Medical Devices: Precision springs in instruments and mechanisms. • Electronics: Micro-springs in connectors and switches. • Industrial Machinery: Shock absorption and motion control systems.

To understand system-level optimization, check out our article on [lightweight design in manufacturing] (link).

Spring manufacturing requires precision, expertise, and specialized processes to ensure high-quality results. That’s why choosing a trusted spring manufacturing company is essential for reliable outcomes.

At Custiv, we specialize in custom spring manufacturing, delivering springs that meet your exact requirements with exceptional accuracy and consistency. As a leading spring manufacturer, we guide you through every stage of the production process to ensure optimal performance and quality. If you’re eager to know more about us or want to avail yourself of custom spring manufacturing solutions from a reliable spring manufacturing company, visit us at Custiv!