Maraging 300 | Maraging 300 Steel

Shapes Available

  • Round Bar


  • Aerospace
  • Manufacturing
  • Medical

Industry Names

  • Maraging 300


  • Specialty Steel


  • ASTM A579 grade 73
  • UNS K93120


  • Aircraft Wing Components and Forging
  • Bearings
  • Bolts
  • Couplings
  • Fan Shafts In Commercial Jet Engines
  • Helicopter Drive Shafts
  • Rocket motor and Missile cases
  • Transmission Shafts


  • Excellent Notch Ductility

Maraging 300 is a readily machined while in the annealed condition.  Full properties achieved through martensitic precipitation aging. Maraging 300 is part of the 18% Nickel Maraging Steel family alongside Maraging 200 and Maraging 250. When working with Maraging steels even though some of them contain Ti (Titanium) and some contain Co (Cobalt) as their strengthening alloy, it’s important to remember that their physical properties differ only slightly and are quite similar. The number in the grade name (300 in this case) corresponds, relatively, not 100% but in most cases, to the tensile strength of that alloy.

This alloy is normally furnished in the annealed condition. This alloy can be easy to machine and relatively soft. However, after heat treating via a precipitation hardening format the hardness increases greatly which makes this steel sufficient for many tooling applications.

Maraging Steel 300 is available in Round Bar. If there’s a Maraging product not listed in the size or shape you need please call Michlin today. Check out our latest video on Maraging right here! If you want you can also watch a more detailed video just on Maraging 300 below:


Please contact us to request a quote. We specialize in hard to find material.

We work closely with many manufacturers in the aerospace & defense industry. We work with NADCAP approved heat treaters and testing laboratories. We can supply DFARS compliant material.

Metal Properties
.2% Yield Strength 290 ksi
Elongation 11 %
Hardness Max, Brinell 304
Ultimate Tensile Strength 294 ksi
Chemical Composition
Al- .1
B- .003
C- .03
Co- 9.0
Mn- .10
Mo- 4.8
Ni- 18.5
P- .03
S- 0.01
Si- .10
Ti- .60
Zr- .01
Go to Top