SelectAlloy 309LMo-C

Stainless Steel / Metal Cored / Gas Shielded


  • The addition of molybdenum (Mo) increases the pitting corrosion resistance in halide-containing environments.
  • Low C, < 0.03 wt%, minimizes carbide precipitation (sensitization) which makes the weld metal more resistant to intergranular corrosion.
  • Metal cored benefits include the ability to successfully bridge gaps when part fit up is not as designed, higher travel speeds with subsequent lower heat inputs at equal amperages, and ability to join thin materials.
  • Primarily used for the surfacing of base metals to improve their corrosion resistance in either a single-layer overlay or for the first layer of a multilayer overlay in conjunction with 316 or 317.
  • Application can also include the welding of Mo-containing stainless steel linings to carbon steel shells, the joining of carbon steel base metals which had been clad with Mo-containing stainless steel, and the joining of dissimilar base metals such as carbon steel to Type 304 stainless steel, for service below 600°F.

Standard Diameters

in (mm)
  • 0.035 (0.9)
  • 0.045 (1.2)
  • 1/16 (1.6)

Welding Positions

Flat and Horizontal

Shielding Gas

  • Ar + 0.5-3% CO₂
  • Ar + 0.5-3% O₂
    Flow Rate: 40 – 50 CFM


Direct Current Electrode Positive (DCEP)


  • ASME SFA 5.22
    • EC309LMo
  • AWS A5.22
    • EC309LMo
    Shielding Gas C Cr Cu Mn Mo Ni P S Si
    98% Ar/2% O₂ 0.03 23.60 0.14 1.70 2.30 13.20 0.019 0.007 0.51

    Packaging (lbs (kg))

    33 (15) Spools, 60 (27.2) Coils, 500 (226.8) Round Drum, 800 (362.9) Hex Drum, 900 (408.2) Hex Drum

    *Some packaging options may not be available depending on diameter and product. Special package options may be available upon request.