Operating requirements are temperature, corrosion, and consideration for potential dissimilar metals in adjoining components.
Alloy wire classes for
springs include:
Carbon steel
- Includes music wire, hard drawn, oil tempered
- Used extensively in commercial applications
- Can be plated
- Useful in ambient conditions
- Most economical
Alloy steel
- Includes chrome silicone and chrome vanadium
- Higher strength than carbon steel
- Improved fatigue life
- Typically, better impact resistance
- Operating temperature to 350 F
- Plating not recommended
- Nominal cost increase over carbon steel
Stainless steel - 300 series - cold drawn
- Most popular corrosion resistant alloy in normal atmosphere when passivated
- Lower strength than carbon steel
- Operating temperature to 350 F
- Most economical of stainless steel alloys
Stainless steel - precipitation hardened
- 17-7PH is most popular spring alloy
- Higher strength, after heat treat, than 300 series
- Operating temperature to 550 F
- Better long-term stability and fatigue than 300 series
- Higher cost
Nickel-based
- Wide selection of alloys for specific applications; examples include Inconel X750, Inconel 718, Inconel 600, Hastelloy, monel
- Most are precipitation hardened
- Operating temperature range is from -300 F to 1000 F, depending on alloy
- Some alloys are sea water corrosion resistant
- Some alloys are good for cryogenic applications
- Substantial cost increase over most other alloys
Cobalt-based
- Similar characteristics as nickel-based
- More corrosive resistant in chlorine and sulfur environments
Copper-based
- Includes brass, phosphorous bronze, beryllium copper
- Best conductivity of all alloys
- Used in electrical and electronic applications
- Can be plated
Titanium
- Up to 30% weight and space savings (low modulus)
- Good fatigue life when shot-peened
- Corrosion resistant (an exception being a chlorine environment)
- Variety of grades for many requirements, including in-body medical applications
- Difficult to fabricate
- Costly
To determine which alloy is best for your application, contact us by clicking "Ask an Engineer".
