This section of the site will hopefully give a brief overview of the problems that we encounter when we start designing a spring, and the options available to solve those problems.

Materials lists the various advantages and disadvantages of the numerous types and sub-types of wire and flat strip that we use here during manufacture.

Sizes gives a useful comparison between metric, Imperial and Standard Wire Gauge sizes of wire and flat strip.

Corrosion suggests suitable solutions for the prevention of corrosion of a spring after manufacture, from simple oils to more complex and expensive plating.

Conversion lists some useful conversion factors for metric to Imperial, and back again, units.

Standards lists a few relevant British Standards for spring materials and tolerances.

Material

There are many different types of material that can be used in spring production. Each material has different compositions and properties.

A spring material needs to have the capacity to store energy by elastic deformation, which covers most metals as well as gases and some plastics. So although gas springs are fairly common, the majority of all springs manufactured are helical springs made from a metal of some sort.

At Kumar Wires and Conductors we keep a large range of materials in stock ready for immediate use. These include the following:

Carbon Steels
Stainless Steels
Low Alloy Steels
Nickel-based alloys
Copper-based alloys
Other Miscellaneous Materials

There are numerous factors that can affect a choice of material for use in a spring.
But, of course, carbon steel will very quickly rust, even in normal operation. Put it in salt water and it will be useless within a few weeks. Stainless steel may be used in these sort of conditions but it is slightly more expensive and not so strong.

The operating temperature will also play a part in your choice of material. The maximum reliable operating temperature of a spring can be as low as 150°C for carbon spring steel, 300°C for stainless, but upto about 550°C for Inconel X750. Call us for further information.

The final choice of material may also depend on other factors such as appearance. Stainless steel or Inconel will not corrode but after heat treatment they are not shiney as would be expected. Stainless steel goes a yellowey colour and Inconel goes dark brown. If a shiny finish is required then the material could be plated after manufacture in which case we would usually suggest using a standard carbon spring steel.

The best way to decide which material is best is to give us a call or send an email for the purpose

Process

• Coiling
• Torsion
• CNC wireforming
• Fourslide
• Power press
• Secondary
• Grinding
• Spot welding
• Stress relieving
• Heat setting
• Fatigue testing
• Computerized SPC and CAD
• In-house tooling

Shapes and Sizes

Wire and flat strip are produced in a range of standard sizes. Wire diameters and flat strip thicknesses usually stick to the Standard Wire Gauge (swg) sizes or to a metric or imperial size. Our wire stocks cover all the standard wire gauges and a lot of non-standard metric and imperial sizes for special cases.

• Round
• Square
• Rectangular
• Special Customized Shapes
• Wire and rod size capabilities from .005" to .250" diameter and flat stock up to .093" thick by 2" wide

Technical Specifications
We keep a complete range of stainless and spring steel wire in stock for immediate use along with a large variety of other materials including Beryllium Copper, Phosphor Bronze, Nimonic 90 and enamel-coated Copper. A considerable investment has also been made in Inconel X750, a very useful alloy of Nickel and Chromium, allowing rapid production and dispatch of springs made with this specialist material (usually for the oil or nuclear industry).