Welding Electrode

E309Mo-16 Stainless Steel Welding Electrode

E309Mo-16 is a rutile-coated stainless steel welding electrode designed for dissimilar metal welding, stainless steel cladding, and Mo-bearing stainless steel applications. It is suitable for welding stainless steel to carbon or low-alloy steel and for 316/316L clad steel. Compliant with AWS A5.4 E309Mo-16, it provides stable arc performance, good weld appearance, and reliable corrosion-resistant weld metal for industrial fabrication and maintenance.

E309Mo-16 for Dissimilar Stainless Steel Welding

E309Mo-16 is an austenitic stainless steel electrode with approximately 22–25% Cr, 12–14% Ni and 2–3% Mo in the all-weld metal. Its alloy design makes it suitable for joining stainless steel to carbon steel or low-alloy steel where conventional stainless electrodes may not provide the required compatibility.

It is also used for stainless steel cladding, buffer layers, and selected repairs involving Mo-bearing stainless steels.

Typical Welding Applications

E309Mo-16 is commonly selected for:

Stainless steel to carbon steel welding

Stainless steel to low-alloy steel welding

316/316L clad steel welding

Stainless steel cladding and buffer layers

Dissimilar metal joints in industrial equipment

Repair welding of stainless steel components

Chemical, petrochemical and process equipment

Why Choose E309Mo-16?

Compared with conventional E309 electrodes, E309Mo-16 contains molybdenum in the weld metal, making it particularly suitable for applications involving Mo-bearing stainless steels and 316-related clad structures.

The electrode offers:

Stable arc with AC or DC+

Smooth and controllable welding operation

Good weld bead appearance

Suitable performance for dissimilar metal joints

Good resistance to weld-metal cracking when correctly applied

Useful corrosion resistance for selected industrial environments

For critical applications, welding procedure qualification should be based on the actual base materials, service conditions and applicable code requirements.

International Classifications

AWS A5.4: E309Mo-16

ASME SFA-5.4: E309Mo-16

JIS Z3221: ES309Mo-16

EN ISO 3581-A: E 23 12 2 R

The exact designation should be confirmed against the applicable standard and manufacturer's certificate for each supply lot.

Typical All-Weld Metal Chemical Composition

Element	Typical / Reference Range (%)
C	≤ 0.12
Si	≤ 1.00
Mn	0.5–2.5
P	≤ 0.040
S	≤ 0.030
Cr	22–25
Ni	12–14
Mo	2–3
Cu	≤ 0.75

Actual chemical composition may vary according to manufacturer, production batch and applicable standard requirements.

Typical Mechanical Properties

Property	Typical Range
Tensile Strength	approx. 660–720 MPa
Elongation	approx. 30–36%

These figures are representative values compiled from commercial product data. Actual deposited-metal properties depend on welding procedure, heat input, test conditions and product batch.

Welding Process & Recommended Current

E309Mo-16 is designed for SMAW (Shielded Metal Arc Welding).

Electrode Diameter	Typical Current
2.0 mm	25–55 A
2.6 mm	50–85 A
3.2 mm	70–115 A
4.0 mm	95–150 A
5.0 mm	135–180 A

Polarity: AC or DC+

Actual current should be adjusted according to welding position, joint design, electrode diameter, base-metal thickness and the applicable WPS.

Base Materials

E309Mo-16 can be considered for welding or cladding applications involving:

18Cr-12Ni-2Mo stainless steels

316 and 316L stainless steel

316/316L clad steel

Austenitic stainless steels

Carbon steel

Low-alloy steel

Dissimilar stainless steel and carbon-steel combinations

For specific combinations, filler-metal selection should consider dilution, service temperature, corrosion environment and required mechanical properties.

E309Mo-16 vs E309L-16

Both electrodes are widely used for dissimilar stainless steel welding, but their alloy designs serve somewhat different applications.

E309Mo-16 contains molybdenum and is particularly relevant to Mo-bearing stainless steels, 316-related cladding and applications where additional Mo in the weld metal is desirable.

E309L-16 is a low-carbon 309-type electrode and is commonly selected where low carbon content and general dissimilar stainless-to-carbon/low-alloy steel welding are the primary requirements.

The final choice should be based on the base materials and service conditions rather than electrode designation alone.

Typical Industrial Applications

E309Mo-16 stainless steel welding electrodes are used in:

Chemical processing equipment

Petrochemical equipment

Pressure and process piping

Stainless steel cladding

Heat-resistant equipment

Industrial maintenance

Dissimilar metal fabrication

316/316L clad components

For demanding applications, GD WELD can review the base-metal grade, thickness, electrode diameter and welding standard to help identify the appropriate consumable.

Supply from GD WELD

GD WELD supplies E309Mo-16 stainless steel welding electrodes for industrial fabrication, maintenance and international procurement.

For quotation or technical confirmation, provide the required electrode classification, diameter, quantity, base material and application. This helps ensure the supplied product matches the intended welding procedure and service conditions.