Flat Springs

Flat springs are made of high carbon steel, nickel-silver steel, high nickel alloy, stainless steel, beryllium copper combination, and phosphor bronze material. Selecting the best type of material is important in spring manufacturing. For example, stainless steel provides better protection against corrosion, and high carbon steel offers durability and rigidity.

Configurations of Flat Springs

Flat springs come in various configurations depending on the application of the product. These are:

• Leaf Springs

  Leaf springs are a type of flat spring made from individual layers, or leaves, of metal. They are important components in automobiles, such as cars. Leaf springs are used in suspensions, automotive design, repair, and steering axles, and they reduce wear and tear on other vehicle parts. Leaf springs are made with high alloy steel or lighter-weight materials such as low-carbon steel.

  Leaf springs come in three basic types:

  • Mono-Leaf Springs

    Consists of one single steel plate placed uniformly from the center to the end of the spring.

  • Multi-Leaf Springs

    Consists of multiple steel plates or metal stacks of tapered leaves attached by a bolt.

  • Parabolic Springs

    Consists of stacked layers of steel attached to the vehicle through a spring eye on both sides of the spring.

  

• Flat Coil Springs

  Flat coil springs are used with a counterweight, which controls the actions of the valves. They are used in the automotive industry, such as in vehicle exhaust systems. They are designed to absorb shocks and are used in seating to provide support.

  

Manufacturing Process of Flat Springs

The process of heating and treating a flat spring is categorized into four steps. These are:

1. Shaping the Spring

   • The first step is shaping the spring. A flat annealed spring steel is measured and marked according to the requirements.
   • Polishing the spring is also required so that the spring will bend correctly.
   • The spring can be bent by either a cold or hot process.
   • After heat bending, it is important to let it cool down without water to not cause scaling in the spring.

2. Hardening the Spring

   • The next step is hardening the spring, which can be done using a carburizing flame.
   • The spring is heated to cherry red by the flame and then quenched in the oil.
   • The heating temperature depends on the type of material used; however, a temperature around 1500 ℉ (815 °C) is ideal.

3. Tempering the Spring

   • Tempering the spring reduces the hardness and brittleness and provides toughness and flexibility to the spring.
   • Before this process, brushing the spring is necessary to remove any scaling on the spring.
   • Tempering temperature depends on the type of spring material.
   • First, the spring is heated to a high temperature and let to cool dry.
   • Tempering can be done using lead baths, burning oil in a pan, or with a torch.

4. Testing the Spring

   • Testing the spring is the last step of the process.
   • The spring is placed in the object where it belongs and tested to see if it can bend or flex.

   

Working of Flat Springs

Flat springs are cupped and have a little curvature that stores mechanical energy. When these springs are exposed to a weighted object, the cupped design causes compression. This compression allows the flat spring to store and release the object's energy. The cupped design will also exert a force against the object being used.

Applications of Flat Springs

Flat springs come in various shapes and sizes according to their applications. They are ideal for use in limited areas. Flat springs are widely used in motors, counterbalances, switches, office equipment, generators, doors, electrical contacts, leaf springs, disc washers, hold downs, shims, clips, and more.