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".