Maraging Steel Springs | C300, C350 Springs

Maraging Steel Springs

Maraging steels are carbon free iron-nickel alloys with additions of cobalt, molybdenum, titanium and aluminium. The term maraging is derived from the strengthening mechanism, which is transforming the alloy to martensite with subsequent age hardening. Air cooling the alloy to room temperature from 820°C creates a soft iron nickel martensite, which contains molybdenum and cobalt in supersaturated solid solution. Tempering at 480 to 500°C results in strong hardening due to the precipitation of a number of intermetallic phases, including, nickel-molybdenum, iron-molybdenum and iron-nickel varieties. C300 grade has tensile strength properties up to 300 Ksi and C350 is up to 350 Ksi while still retaining excellent ductility.

Typical applications areas include :

  • Aerospace, e.g. undercarriage parts and wing fittings
  • tooling & machinery , e.g. extrusion press rams and mandrels in tube production, gears
  • Ordnance components and fasteners.

Maraging Steel Spring Types

Maraging Steel Extension Springs Maraging Steel Wires Maraging Steel Torsion Springs Maraging Steel Compression Springs

Maraging Steel Spring Properties

Specification Maraging C300 Maraging C350
Nominal Composition Nickel(Ni):18.0 - 19.0
Cobalt(Co): 8.5 - 9.5
Molybdenum(Mo): 4.6 - 5.20
Iron(Fe): Balance
Nickel(Ni):18.0 - 19.0
Cobalt(Co): 11.5 - 12.5
Molybdenum(Mo): 4.6 - 5.20
Density 0.289 lb./in3, (8.0 g/cm3) 0.292 lb./in3, (8.1 g/cm3)
Modulus of Elasticity (E) 27.5 x 106 psi 29 x 106 psi
Modulus of Rigidity (G) 10.6 x106 psi 11.2 x 106 psi
Coefficient of Expansion 5.6 µin/in.-°F (70°F to 900°F) 6.3 µin/in.-°F (70°F to 900°F)
Electrical Resistivity 68.5 µΩ.in, (174 µΩ.cm) 68.5 µΩ.in, (174 µΩ.cm)
Thermal Conductivity 176Btu-in/ft2hr-°F, (25.3 W/m-K) 176Btu-in/ft2hr-°F, (25.3 W/m-K)
Min Size 0 0
Max Temp 482oC (900oF) 482oC (900oF)
Uses of Maraging Steel Springs It is resistant to crack propagation and used in aircraft or high-performance racing springs C350 alloy is heavier and harder than C300 due to higher amounts of Cobalt. Used in high end military applications, such as, recoil springs for heavy guns.