Spring Steel Materials Guide
How to choose the right spring steel for load, fatigue, corrosion and temperature – with ASTM, EN, JIS and GB grade cross-references.
Why Material Choice Matters
The material determines everything about a spring: how much force it can carry, how many cycles it survives, how it behaves in corrosive or high-temperature environments, and what it costs. Selecting the right spring steel is the single most important decision in a spring design.
Springs are almost always made from wire that is cold drawn or heat treated to high strength, then formed and stress relieved. The most common families are carbon steels, alloy steels, stainless steels, copper alloys and high-temperature alloys.
This guide explains each family, lists the international grades you will meet on drawings and specifications, and gives practical selection guidance for real applications.
1. Carbon Spring Steels
The workhorses of the spring industry – strong, inexpensive and easy to form.
Music wire (piano wire) is the toughest common spring wire. It is cold drawn to a very high tensile strength with a bright finish, which makes it ideal for small precision springs and dynamic applications such as garage door springs. Key grades: ASTM A228, EN 10270-1 (patented cold drawn), JIS G 3522 (SWP), GB/T 4357.
Hard drawn wire (ASTM A227, JIS G 3521 SWC) is a lower-cost general-purpose wire for light static springs where fatigue life is not critical.
Oil-tempered wire (ASTM A229) is quenched and tempered after drawing, which gives good fatigue resistance at moderate cost; it is widely used for compression springs in vehicles and machinery. ASTM A230 is the higher-quality oil-tempered carbon valve spring wire used where severe dynamic loading is expected. European and Asian equivalents: EN 10270-2, JIS G 3560 (general) and JIS G 3561 (valve spring), GB/T 18983.
Carbon steels are not corrosion resistant and lose strength above roughly 120-150 deg C. They normally need a protective coating or an oil film in service.
2. Alloy Spring Steels
Chromium-vanadium and chromium-silicon grades for higher stress, fatigue and temperature.
Chromium-vanadium wire (ASTM A231) resists fatigue and shock, tolerates higher stresses and operates at higher temperatures than carbon steel. It is a classic choice for engine and suspension springs. ASTM A232 is the premium Cr-V valve spring quality with even tighter control. Equivalents: EN 10270-2 grade VD, JIS G 3560 SWOCV-V, GB/T 18983 (50CrVA family).
Chromium-silicon wire (ASTM A401) offers the highest strength of the common alloy wires with excellent fatigue life, and is used for heavy-duty and high-temperature applications such as commercial vehicle suspension. Equivalents: EN 10270-2 SiCr grades, JIS G 3560 SWOSC-V, GB/T 18983 (60Si2CrVA family).
Alloy steels are still not corrosion resistant; they need a coating or oil film for outdoor service.
3. Stainless Spring Steels
Corrosion resistance and temperature capability at a higher cost.
Austenitic stainless wire (ASTM A313 types 302/304/316, EN 10270-3, JIS G 4314 SUS302/SUS304, GB/T 4240) is the default choice for corrosive environments, food and medical equipment, and wash-down applications. Type 316 adds molybdenum for better pitting resistance in marine and chloride environments.
Precipitation-hardening grades such as 17-7 PH (EN 10270-3 grade 1.4568, JIS G 4314 SUS631) give much higher strength with good corrosion resistance for demanding dynamic springs.
Stainless springs cost roughly twice as much as carbon steel but need no coating. They also perform well at cryogenic temperatures and up to about 250-300 deg C depending on grade.
4. Copper Alloys and High-Temperature Alloys
Phosphor bronze and beryllium copper are chosen where electrical conductivity, non-magnetic behaviour or corrosion resistance matters – for example contacts, instruments and precision mechanisms. They are softer and weaker than steel, and are normally supplied to the relevant copper alloy wire specifications.
For service above roughly 300 deg C, high-temperature alloys such as Inconel X-750 and Nimonic 90 maintain useful spring strength where ordinary steels relax. These are specialist materials supplied with mill certificates; design data should be confirmed with the material supplier before quoting.
International Grade Cross-Reference
Common spring wire families across the four main standard systems. Confirm the exact grade, diameter range and property class with your spring manufacturer before production.
| Music wire (high carbon) | ASTM A228 | EN 10270-1 (DH/SH) | JIS G 3522 (SWP) | GB/T 4357 |
| Hard drawn carbon | ASTM A227 | EN 10270-1 | JIS G 3521 (SWC) | GB/T 4357 |
| Oil-tempered carbon | ASTM A229 | EN 10270-2 (FD) | JIS G 3560 (SWO) | GB/T 18983 |
| Oil-tempered valve spring | ASTM A230 | EN 10270-2 | JIS G 3561 (SWOV) | GB/T 18983 |
| Chromium-vanadium | ASTM A231 | EN 10270-2 (VD) | JIS G 3560 (SWOCV-V) | GB/T 18983 |
| Chromium-silicon | ASTM A401 | EN 10270-2 (SiCr) | JIS G 3560 (SWOSC-V) | GB/T 18983 |
| Stainless austenitic (302/304/316) | ASTM A313 | EN 10270-3 | JIS G 4314 (SUS302/SUS304) | GB/T 4240 |
| Stainless 17-7 PH | ASTM A313 (631) | EN 10270-3 (1.4568) | JIS G 4314 (SUS631) | GB/T 4240 |
Selection Guidance at a Glance
High Load and Fatigue
Choose oil-tempered (A229/A230) or alloy Cr-V and Cr-Si wire (A231/A401), design below the endurance limit, and specify shot peening for dynamic duty.
Corrosive Environment
Use stainless (A313 / EN 10270-3) or protect carbon steel with zinc, Dacromet or another suitable finish.
High Temperature
Above about 150 deg C move from carbon to Cr-Si or stainless; above about 300 deg C use Inconel X-750 or a similar superalloy.
Cost-Sensitive Static
Hard drawn (A227) or music wire with a simple finish usually gives the lowest cost per spring.
Frequently Asked Questions
Q: What is the cheapest spring material?
Hard-drawn carbon steel wire (ASTM A227) for light static springs, or music wire (ASTM A228) for small dynamic springs. For larger quantities, alloy grades can still be very competitive when fatigue life matters.
Q: When should I choose stainless instead of coated carbon steel?
When wash-down, marine, food, medical or long-life outdoor service makes coating maintenance impractical. Stainless costs more but needs no finish and survives where coatings would chip or corrode.
Q: Can you manufacture to a grade from another standard system?
Yes. Chenji works with ASTM, EN, JIS and GB grades every day. Send your drawing or wire specification and we will confirm the equivalent grade, property class and heat treatment before production.
Need a Spring in a Specific Material?
Send your drawings and we will confirm the grade, heat treatment and finish – then manufacture to ASTM, EN, JIS or GB specifications.