Ferrium® M54®


Ferrium M54 (AMS 6516; MMPDS-09) is an ultra-high strength and high fracture toughness steel with excellent fatigue resistance and high resistance to stress corrosion cracking (SCC).

M54 steel is one of the strongest and toughest steels in the world.

QuesTek designed M54 steel using Integrated Computational Materials Engineering (ICME) technologies under Navy SBIR funding to be a cost-effective alternative for AerMet®100 (AMS 6532).

M54 steel is double vacuum melted (i.e., vacuum induction melted and then vacuum arc remelted or "VIM/VAR") for high purity, leading to much greater fatigue strength.

Improved M54 Steel Properties versus Incumbent Materials

A comparison of typical properties is shown in the table below:

Additional information can be found in the M54 Datasheet or on Carpenter's Ferrium M54 page.


M54 steel is being used in demanding applications in the aerospace, energy, oil and gas and racing industries as an upgrade in performance from Maraging 250, 4340, 300M (BS S155) and other steels to reduce component weight or size or increase service life, safety and reliability.

Two example leading applications of M54 steel include the following:

  • Funded under Navy SBIR Phase II Topic #N07-032, QuesTek delivered three prototype arresting shanks made with M54 steel for the T-45 platform, and the Navy qualified M54 steel to >2x the service life over the existing material, with a cost savings to the Navy of >$3 Million. Work under this program has led to QuesTek serving as prime contractor under a $5 million toll manufacturing contract to produce and deliver 60 T-45 hook shanks in 2016/2017. The first delivery of 8 hook shanks was in January 2016. 
  • An oil and gas services company has designed a new case running tool using M54 steel to replace 4340. Due to the much greater strength and toughness of M54 steel, the case running shafts can withstand much greater loads than when produced from 4340.

Aerospace and defense applications: landing gear, rotorshafts, driveshafts, arresting tailhooks and hookshanks, actuators, armor, munitions, gun barrels, and blast-resistant or impact containment devices.

Energy industry applications: lifting shafts, driveshafts, couplings or collars.

Racing applications: driveshafts, crankshafts, and connecting rods.

If you need an ultra-high strength steel with a high resistance to corrosion, see Ferrium S53.

If you need a tough, strong core but greater surface hardness, see carburizing-grade Ferrium C64.


M54 steel can be considered for demanding applications where superior fatigue resistance and SCC resistance is advantageous. Benefits of using M54 steel vs. AMS 6532 Maraging 250, 4340, 300M or other high-strength steels can include:

  • Reduce the cost for parts currently using AMS 6532, while also gaining improved material properties. In addition to containing about 50% less cobalt than AMS 6532, M54 steel has robust thermal processing windows to reduce manufacturing waste/re-work.
  • Improve the durability, or reduce the size and weight, of parts currently using 4340, Maraging 250, 300M or other alloys, by leveraging the superior fracture toughness, fatigue resistance and other properties of M54 steel.
  • Reduce the occurrence of difficult-to-predict SCC failures of parts currently using AMS 6532, 4340, Maraging 250, 300M or other alloys, and related expenses for part condemnation and equipment failure/downtime. M54 steel has demonstrated approximately 400% greater resistance to SCC than AMS 6532 at OCP, as measured by ASTM F1624.

Forging, Machining, Heat Treatment and Finishing Processes

Processing of M54 steel is similar to other quench and tempered martensitic secondary-hardening steels. Vacuum heat treatment and vacuum tempering is recommended to avoid surface decarburization. After quenching to room temperature M54 steel is subjected to cryogenic treatment to assure a complete martensitic transformation. M54 steel is typically tempered around 960°F (516°C).

For detailed information about forging, machining, heat treating and finishing processes of M54 steel, please refer to our Manufacturing and Thermal Processing of M54 Steel document.

M54 Steel Price and Availability

Carpenter Technology produces and typically keeps an inventory of M54 steel in round bar form of the following sizes, usually with immediate shipment and no minimum order: 1.0625", 1.25", and 4". There are a few thousand pounds of 7" and 7.625" OD currently available but these sizes will not be kept in inventory in the future unless requested.

Other sizes will be added in time, and they can produce custom diameters, round corner square and octagon, although longer lead times and minimum orders in the range of 800 lbs are likely.

For pricing, inventory availability and lead time please contact Carpenter Latrobe facility by phone (800-241-8527) or e-mail at service@cartech.com. You may also contact the Reading facility by phone (800-572-2800 or 800-245-5030) or e-mail at sales@cartech.com

Technical Assistance

If you have a specific application engineering or technical question that is not answered by the processing document above, then feel free to Contact Us.

Design and Development Background

In December, 2013, M54 steel was approved for inclusion with A- and B-basis minimum design allowables in the Metallic Materials Properties Development and Standardization (MMPDS)-09.

In July 2012 we announced a NAVAIR-funded SBIR Phase II contract to demonstrate M54 steel for use in U.S. Navy aircraft tailhooks.

In June 2012 S-basis design allowables for M54 were approved for use in the MMPDS handbook.

In June 2012 a formal machining study of M54 steel was completed, results of which were approved for release in 2013. Results indicate that in general M54 steel machines faster than AMS 6532 for major material removal turning operations.

In 2011 SAE International issued AMS 6516 specification for M54 steel.

In 2011 we co-authored a technical paper that evaluated protection schemes for ultrahigh-strength steels (including M54 steel) for landing gear applications. The paper concluded that a cadmium, chromate, primer and paint protection scheme on M54 steel did not show as much evidence of breakdown as the same scheme on either 300M or 4340 after 500 hours of salt fog testing per ASTM B117; comparative data for zinc-nickel protection performance was also presented (see below).

In 2011 we completed a NAVAIR-funded SBIR Phase II program to further design and develop M54 steel as a lower-cost, high-performance landing gear steel.

In 2011 we completed a NAVAIR-funded SBIR Phase I program that evaluated M54 steel as a material for use in tailhook components, used to abruptly arrest and stop aircraft landing on aircraft carriers.

In 2010 we announced that Latrobe Specialty Steel Co. (now Carpenter Technology) is the initial firm licensed to commercially produce and sell M54 steel.

Note: AerMet is a registered trademark of CRS Holdings, Inc., a subsidiary of Carpenter Technology Corp.

Relevant files


Material Data Sheets


  • AA&S 2012

    Ferrium M54: A New Fatigue-Resistant, Lower Cost, Ultra-High Strength Steel for Landing Gear and Arrestment Applications - April 3, 2012

Press Releases