Maraging 300 (UNS K93120)

Maraging 300 (UNS K93120) is an 18% nickel, cobalt strengthened steel (C-type) with excellent properties, workability and heat treatment characteristics. Maraging material is supplied in the annealed and descaled condition. The alloy is very tough, relatively soft (RC 30/35), readily machined or formed. Maraging provides a high value for critical parts in aerospace, structural, component and tooling applications.

Equivalent Grades

Maraging 300

Chemical Composition, %

Maraging 300≤0.03≤0.10≤0.10≤0.01≤0.01≤0.5018.0-19.08.5-9.54.6-5.20.05-0.150.5-0.8≤0.50Bal

Typical Physical and Mechanical Properties (RT, Annealed+Aged)

Density, g/cm3Melting Point, ℃Tensile Strength, MPaYield Strength, MPaELongation, %Hardness, HRB

Available Products and Specifications

Rod, Bar, Wire and ForgingsASTM A 538, AMS 6514
Plate, Sheet and Strip
Pipe and Tube
Welding Product


Maraging 300 is a nickel/cobalt steel alloy that is essentially carbon-free, other alloying elements include moly, aluminum and titanium. This combination creates a superior maraging steel that maintains numerous beneficial features, including:

  • Extremely tough
  • Relatively soft
  • Maintains high strength & toughness
  • Ultrahigh tensile strength
  • Resists corrosion & crack propagation
  • Excellent cleanliness & polishability
  • Readily weldable


Commercial applications for this engineering material include:

  • Missile casings
  • Tooling
  • Ordnance mounting blocks
  • High performance
  • Autosport components
  • CouplingsJet engine and helicopter drive shafts
  • Load cells