What Is Spring Steel?

As a material vital to numerous industries, spring steels hold certain characteristics that set them apart from other types of steel. But what is spring steel and what makes it so useful? In this article, we’ll discuss exactly what spring steel is, its properties, various grades and common applications.

What is the composition of spring steel?

The selection of materials used in spring fabrication and design in general is determined by knowing the tensile and yield strengths of the various alloyed metals. In making spring steel, in addition to its carbon content, which is generally in the range of 0.5% to 1.0%, spring steels may also be alloyed with combinations of nickel, manganese, chrome, vanadium, molybdenum or other elements.

However, the one common element that is a must in the composition and manufacture of spring steels is silicon. This material is highly regarded for its durability as well as its ability to retain its shape and flexibility. Its alloying properties are not only particularly well-suited for use in alloy spring steel applications, but its characteristics help give the material its defining high-yield strength.

What is the difference between steel and spring steel?

Steel is an alloy of iron and carbon, with other elements added to enhance its properties. There are different types of steel, each with unique properties, depending on their specific composition and processing techniques.

Spring steel is a specific type of steel, engineered for its high yield strength, elasticity, hardness and resilience, which makes it suitable for use in springs and other applications such as retaining clips and tabs.

In terms of which is better, it really depends on the application. For components like springs, automotive suspension components, and other mechanical parts that must withstand cyclical stresses, spring steel is superior to alloy steels.

However, for applications that don’t require high elasticity, resilience, and tensile strength, regular or other forms of steel will be suitable and more cost-effective. There are downsides to using spring steel such as the extra considerations needed for machining and welding it.

Unique properties

Spring steel has many unique properties that make it ideal for producing springs and other similar components, including:

• Resilience — Spring steel is highly resilient and can return to its original shape after being bent or stretched.
• Strength and durability  — Spring steel can support heavy loads without breaking, and is particularly good at withstanding cyclical loads that would fatigue other alloys.
• Elasticity — Spring steel can be formed, shaped, and post-heat treated without losing its shape.

Hardening

The process of hardening spring steel is another important step in giving the material its high yield strength. Hardening can occur through heat treatment or a process referred to as work hardening; this is the hammering, rolling, drawing or other physical means that can be applied to increase its hardness.

Hardening via heat treatment, as the name suggests, is achieved by heating up the steel, and then quenching the material to bring it down to ambient room temperature. After heat treatment, the steel is tempered to ensure that it does not become brittle as well as to prevent or relieve it of internal stresses.

Heat-treated spring steel is used for such products as saw blades, knives, and flat springs. Work hardening methods are achieved by rolling the material to reduce its thickness. The process increases the material’s tensile strength and produces spring steel sheets, strips, rods and bars.

Spring steel grades

Popular spring steel grades include the following SAE grades (ASTM grades):

• 1074/1075
• 1095 (A684)
• 5160 (A689)
• 9255
• 301 (A666) Spring tempered stainless steel

Common uses & applications

As a general-use steel, spring steel has a wide range of commercial applications. You can find it in just about any piece of manufacturing equipment, including:

• Clips & fasteners — With high-strength and good fatigue strength resistance, spring steel is ideal for creating clips and fasteners that hold things together.
• Springs — From everyday machinery to vehicular parts, spring steel is most commonly used to create coil springs, compression springs, torsion springs, and leaf springs.
• Medical equipment — Spring steel is often used to create medical instruments, like surgical tools and orthodontic appliances.
• Machinery — Spring steel is used for manufacturing machinery and equipment, from lawnmowers and aircrafts to conveyors and pumps.
• Hand tools — With its high strength, spring steel is perfect for producing strong, durable tools like pliers, wrenches, and scissors.

Final thoughts

Spring steel is a unique and versatile material with exceptional properties such as high yield strength, elasticity and resilience. Its composition and heat treatment processes set it apart from regular steel, making it ideal for various applications, including springs, clips, fasteners, and machinery. Contact us at Metal Supermarkets to learn more about spring steel grades and how they can fit your specific needs.