Custom Carbon Alloy Steel Springs

Coiling Technologies manufactures carbon and low alloy steel springs for a variety of applications and industries. High-carbon steel wire is very economical and is the most common type of spring steel. These fall under the hard-drawn and oil-tempered material grades. These grades include:

  • ASTM A227 - Also known as Hard Drawn Wire
  • ASTM A228 - Also known as Piano Wire, Music Wire, JIS G 3522
  • ASTM A229 - Also known as Oil Tempered Wire

High carbon steel is available in various grades and can provide high strength and good ductility which makes it ideal for various types of springs and a very popular and cost-effective option for spring making.

Low alloy carbon steel Features & Benefits

Low alloy carbon steel is more suitable for elevated temperatures up to 450 F (230 C) and repeated shock loading the most common grades for these types of applications is Chrome Vanadium (CrV) and Chrome Silicon (CrSi) material grades, ASTM A 231 and ASTM A401 respectively. These material grades are more commonly used in high-stress dynamic conditions like engine valve springs and high-stressed suspension applications for higher-performance vehicles. Typically, these steel grades require only tempering after coiling.

For Larger material diameters above 0.625” various steel grades like 5160 H, 4161, 6150 and 51CrV4 are commonly used. These material grades are not pre-tempered and typically must be heat treated to obtain their optimum material and tensile strength properties.

Industries Using Carbon Alloy Springs

These springs are readily available and extensively used in commercial applications. It is not suitable for operating in corrosive environments without applying a coating or metallic conversion or electroplating process, extreme temperatures, or repeated dynamic shock loading. There are many industries using carbon alloy springs for their industrial applications. 

Common Carbon Alloy Steel Grades Springs

Coiling Technologies can produce springs made of Carbon and low alloy steel. The available size ranges are from 0.008” wire to 2.5” bar.

Common carbon steel material grades are:

  • ASTM A227
  • ASTM A230
  • ASTM A232
  • ASTM A231
  • ASTM A228
  • ASTM A229
  • ASTM A30
  • ASTM A401
  • ASTM A679
  • ASTM A 689
  • ASTM A877
  • ASTM A878
  • ASTM A1000
  • BS2803
  • BS521
  • DIN 17223
  • JIS3522
  • JIS3560
  • JIS3561
  • JIS3565
  • JIS3566

Take a look at some of our Carbon & Alloy Steel grades below or contact us today for more information on our custom spring manufacturing services.

Custom Carbon Alloy Steel Springs FAQs

What does the carbon alloy category cover?

Coiling Technologies manufactures carbon and low alloy steel springs for a wide range of applications and industries. High carbon steel wire is the most common spring material and the most economical, and it falls under the hard drawn and oil tempered material grades: ASTM A227, ASTM A228, also known as piano wire or music wire and cross referenced to JIS G 3522, and ASTM A229. High carbon steel comes in several grades and provides high strength with good ductility, which is why it covers most spring types and most commercial applications.

What is the size range for carbon and low alloy steel springs?

The published range runs from 0.008 in wire up to 2.5 in bar. Above 0.625 in the material changes character. Below that point, springs are typically made from pre-tempered wire that needs only a stress relief after coiling. Above it, grades such as 5160H, 4161, 6150, and 51CrV4 arrive without a mill temper and must be heat treated after forming to obtain their optimum material and tensile strength properties. That crossover determines the process route and the inspection plan, so it is worth pinning down early in a design.

How hot can a low alloy carbon steel spring run?

Low alloy carbon steel is suitable at temperatures up to 450 degrees F (230 degrees C) along with repeated shock loading, and the grades that reach that range are chrome vanadium and chrome silicon, specified as ASTM A231 and ASTM A401 respectively. Those two are the grades used in engine valve springs and high stressed suspension applications on higher performance vehicles, and they typically require only tempering after coiling. Plain high carbon grades stop far lower. Beyond 450 degrees F the carbon and low alloy family is the wrong choice, and stainless or a nickel alloy is required.

Which carbon and alloy steel grades can CTI work with?

Common grades include ASTM A227, A228, A229, A230, A231, A232, A30, A401, A679, A689, A877, A878, and A1000, along with BS2803, BS521, DIN 17223, and JIS 3522, 3560, 3561, 3565, and 3566. Those are customer specifiable material standards, and CTI can build and heat treat springs to meet them. The list spans hard drawn, oil tempered, music wire, chrome silicon, and chrome vanadium material, so grade selection can follow the stress and temperature requirement instead of following whatever happens to be on hand. Name the specification and its revision on the purchase order, since test and surface requirements differ between them.

What are the limitations of carbon alloy springs?

Carbon and low alloy steel springs are not suitable for operating in corrosive environments without a coating, a metallic conversion, or an electroplating process, and they are not suitable for extreme temperatures or repeated dynamic shock loading outside the grades built for it. Plating brings its own constraint, since hydrogen absorbed during electroplating can embrittle a hardened spring unless it is baked promptly afterward. CTI applies powder coating in house as one alternative. Where corrosion or temperature drives the requirement, stainless steel, Inconel, or a nickel alloy is the right answer.

What makes CTI a good fit for carbon alloy spring work?

Design, prototyping, coiling, heat treating, non-destructive testing, shot peen, powder coating, and inspection all take place in one Houston facility under a single ISO 9001:2015 certified quality management system, with no outsourcing between operations. Carbon and low alloy springs depend on thermal processing and surface condition for nearly every property on the drawing, so keeping those steps in house keeps them controlled and traceable back to incoming raw material. CTI has manufactured short run and custom springs since 1976 and belongs to the Institute of Spring Technology and the Spring Manufacturers Institute.