Molybdenum Arc-Cast

Most of the pure molybdenum and molybdenum-base alloys used today are produced by the powder metallurgy method in which starting ingots are made by pressing and sintering molybdenum powder to accomplish both consolidation and purification. Molybdenum ingots can also be consolidated by vacuum arc casting, a method in which a preformed electrode is melted by arc formation in a water-cooled mold. The greatest advantage arc-casting offers is in its ability to provide large dense ingots. Mill products made from arc-cast ingots are specified when low gas content is desired. However, because of improvements in the technique of making pressed and sintered ingots, the gas content of both types of ingots are now about the same. After pressing and sintering, or arc-casting, molybdenum ingots are worked by forging, rolling, swaging, and drawing into various mill products. Molybdenum and its alloys are also readily extruded to form a variety of shapes.

There is very little difference in the physical properties of molybdenum produced from pressed and sintered ingot versus arc-cast ingot. The mechanical properties of molybdenum and molybdenum alloys mainly depend on the amount of working performed below the recrystallization temperature and on the ductile-to-brittle transition temperature. Compared to arc-cast products, bars or forgings of powder metallurgy products may exhibit greater tendencies to chip out at the edges and to develop slightly ‘pitted’ surfaces in turning, shaping and milling. The minimum recrystallization temperature for molybdenum is 900 oC. Arc-cast molybdenum is normally supplied in the stress-relieved condition.

Nominal Composition in Percentage:

C                     0.010 Max

Fe                    0.010 Max

Ni                    0.002 Max

O                     0.010 Max

N                     0.0015 Max

Mo                    99.97 Min

Mechanical Properties of Arc-Cast Molybdenum Bar (65 oC - 85 oC):

                                                                                     Tensile                Yield Strength

                                                   Strength                (0.2% Offset)             Elongation

                 Diameter                   Minimum                   Minimum                   Minimum 

Inches                                mm                  ksi          MPa           ksi          MPa            %

0.125" to 0.406"                3.2 - 10.3              90           620            75           515             30

Over 0.406" to 0.875"       10.3 - 22.2             90           620            75           515             25

Over 0.875" to 1.125"       22.2 - 28.6             85           585            70           485             25

Over 1.125" to 1.875"       28.6 - 47.6             75           515            65           450             20

Over 2.875" to 3.5"          73.0 - 88.9              65           450            55          380             10

Home Page Content Under Periodic Table


Click on the Alloy to go to the Online Catalog page.


Welcome to

ESPI was incorporated in 1950 with a mission to provide a competitive source for high purity metals, metal compounds and alloys. We are a valuable resource for virtually all major universities worldwide, global corporate R&D laboratories, thousands of domestic and international manufacturing companies and all U.S. government research laboratories. ESPI offers unique advantages often unavailable from larger organizations with no minimum order size & all business hour calls are handled by a competent sales representative. Automated answering systems and voice mail are not an option at ESPI.

Located within our fabrication facility is the melting department, forging & shaping areas, and the rod & wire, and sheet & foil departments providing the following manufacturing capabilities:

  • Casting of pure metals and alloys
  • Vacuum arc melting
  • Induction melting
  • Rod and wire drawing/extrusion
  • Sheet, foil and ribbon rolling
  • CNC milling and machining

Tel: 541-488-8311 - Email: - or click the "Live Help/Chat Now" icon, upper right.



ESPI produces and sells 68 elements and dozens of alloys in various forms for your custom needs. Click on the forms below to be directed to detailed information on manufacturing.



At We Keep Good Company

Aerospace and Defense
Northrop Grumman, Hewlett Packard, IBM, Lockheed-Martin, Hughes, Boeing, General Dynamics, Aerojet, Litton, General Electric

Medical Instruments & Technology
Cintron, Hologic/Lorad, Varian, Siemens Medical, St Jude Medical, ArthroCare, GE Medical, Harvard Medical School, City of Hope Medical Center, American Medical Systems, Cedars Sinai Medical Center

Atomic Energy of Canada, CNRS, European Synchrotron Radiation Facility, INRS, Alberta Research Council, National Research Council of Canada, UNAM, CISRO, CERN

Stanford, UCLA, Harvard, Georgia Institute of Technology, Caltech, Johns Hopkins University, University of Arizonia, Penn State, University of Michigan, Princeton, Yale, University of Wollongong, University of Tokoyo, University of Toronto, Tulane, University of New South Wales, Max-Planck Institute, University of Freiburg

Government Research Labs
JPL, Los Alamos National Lab, Battelle Pacific NW National Lab, US Department of Energy, Argonne National Lab, Brookhaven National Lab, Naval Oceans Systems Center, US Air Force, Lawrence Berkeley National Lab, NASA

Green Energy
Origin Energy Solar, First Solar, Schott Solar, SunPower Corporation, Nanosolar, Inc.