About Smiths Advanced

We are a leading stockholder and global supplier of metals and plastics into Aerospace & Space, Chemical, Defence, Medical, MRO, Naval, Nuclear, Oil & Gas and Power industries.

We make high quality materials available in a fast, cost-effective and convenient package and provide a consistent supply path for all our customers.

UKAS Laboratory

Maraging 300 Steel Bar

Outstanding weldability.

The strength and toughness characteristics of our Maraging 300 steel bars are exceptional.

Our Maraging 300 steel bars are strengthened with cobalt to create exceptional toughness and strength.

Maraging 300 steel is stronger than 250, but fracture toughness is slightly lower. The alloy offers high strength with a tensile strength of 2035 MPa. The strength and toughness characteristics of Maraging 300 are exceptional. Other performance benefits include excellent notch ductility, good ductility, outstanding weldability and good resistance to crack propagation. The steel alloy contains 9% cobalt and 4.8% molybdenum and is finished in the solution annealed delivery condition.

Mechanical Strength

The alloy retains its mechanical strength at elevated temperatures up to 450°C and high toughness with good notch impact toughness at -50°C. Maraging 300 steel can be machined to close dimensional tolerances because low-temperature maraging treatment results in an alloy with minimal distortion. Our product can also be nitrided if required.

Maraging 300 Steel Bar Datasheet


Machinability of the alloys is good, primarily because steels of this type have low carbon content. Maraging 300 steel suffers no loss in malleability when machined and retains mechanical properties. Applications for this material include missile and rocket cases, actuators and aircraft landing gears.

Stock Availability

Smiths Advanced Metals stocks Maraging 300 steel bars in the annealed condition and in closer incremental sizes to suit your particular engineering requirements.

Product Features:

    UNS K93120

    Aircraft parts
    Gears for machine tools
    Pump impellers

    Excellent mechanical properties
    Very high strength
    Excellent notch ductility
    Good resistance to crack propagation

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