ThePipingMart Blog Welding Electrodes AWS Class ER312 MIG & TIG Welding Rod – Composition, Properties, and Uses

AWS Class ER312 MIG & TIG Welding Rod – Composition, Properties, and Uses

AWS Class ER312 MIG & TIG

Welding is a process that requires skill, knowledge, and experience. It is the process of joining two or more pieces of metal together. There are various types of welding, and each type depends on the type of metal being joined. One type of welding that is commonly used in the industry is MIG and TIG welding electrode. This blog post will focus on AWS Class ER312, which is suitable for MIG and TIG welding. We’ll explore its composition, physical and mechanical properties, uses, heat treatment, and corrosion resistance.

What is AWS Class ER312 MIG & TIG?

AWS Class ER312 MIG & TIG is an American Welding Society (AWS) certification required to perform welding processes in the automotive industry. This course covers gas metal arc welding (GMAW), including both Metal Inert Gas (MIG) and Tungsten Inert Gas (TIG). It also teaches technical skills, safety standards, and proper equipment handling. Students will learn how to properly weld with different materials, as well as the use of filler metals and their selection process. Additionally, they will gain an understanding of welding symbols commonly used in this field, along with testing specifications for parts made from various metals. With this course, you’ll be able to successfully work on high-quality automotive projects that meet exact customer requirements!

ER312 MIG & TIG Welding Rod Composition

AWS Class ER312 is classified under the ‘A5.9 standards, primarily composed of stainless steel. It contains nickel, molybdenum, and chromium. The nickel content provides excellent resistance to high-temperature oxidation, while the molybdenum and chromium content provides excellent corrosion resistance in various environments. The copper content is added to improve its electrical conductivity.

C Cr Ni Mo Mn Si P S Cu
0.15 28.0-25.0 8.0-10.5 0.75 1.0-2.5 0.30-0.65 0.03 0.03 0.75

ER312 MIG & TIG Coated Rod Physical Properties

AWS Class ER312 has excellent physical properties. It is a filler wire that is available in various sizes and lengths. Its density is 7.9 g/cm3, with a melting point between 1370°C and 1400°C. The wire has a smooth surface, which makes it easy to feed through the MIG or TIG welding gun. Additionally, the wire is available in either bare or coated with copper, which helps in making it easier to handle.

ER312 MIG & TIG Welding Rod Mechanical Properties

AWS Class ER312 is an austenitic stainless steel welding wire with excellent mechanical properties. It has a tensile strength ranging from 550 to 750 MPa and a 35-45% elongation. The wire provides excellent weld deposits that are machinable, crack-resistant, and ductile. AWS Class ER312 wire also offers excellent corrosion resistance, making it suitable for many applications.

Yield, kpsi:
Tensile Strength, kpsi: 109
Elongation%, min: 45

ER312 MIG & TIG Coated Rod Trade Name

Class UNS Oxford Alloys BOHLER UTP
ER312 S31380 Alloy 312 BOHLER THERMAINT 30/10 UTP A 651

ER312 MIG & TIG Welding Rod Parameters

Diameter Process Volt Amps
in (mm)
.023 (0.6) GMAW 14-19 30-85
.030 (0.8) GMAW 15-20 45-125
.035 (0.9) GMAW 16-22 60-150
.045 (1.14) GMAW 17-22 90-210
1/16” (1.6) GTAW 12 80-150
3/32” (2.4) GTAW 12 150-250
1/8” (3.2) GTAW 12 200-375

ER312 MIG & TIG Coated Rod Uses

AWS Class ER312 is widely used in different industries, such as food and beverage, petrochemicals, and pharmaceuticals. AWS Class ER312 is suitable for welding austenitic stainless steels such as 304,316, 321, and 347. Additionally, it is used in welding dissimilar metals such as mild steel to stainless steel and even copper to stainless steel. AWS Class ER312 wire also provides excellent weld deposits for repairing damaged parts or restoring damaged surfaces.

ER312 MIG & TIG Coated Rod Heat Treatment

Heat treatment is essential, particularly when welding alloy stainless steel. The recommended heat treatment for AWS Class ER312 is a solution annealing process that involves heating the welded steel to 1050 – 1120°C. After heating, the metal should be rapidly cooled to avoid the formation of carbides that can cause cracking. Heat treatment is essential to prevent stress cracks or intergranular corrosion, especially when welding stainless steel.

ER312 MIG & TIG Welding Rod Corrosion Resistance

AWS Class ER312 provides excellent resistance to corrosion, particularly against sulfuric and phosphoric acids. Additionally, the nickel content in AWS Class ER312 resists high-temperature oxidation. With excellent corrosion resistance and high-temperature oxidation resistance, AWS Class ER312 is perfect for many applications that require corrosion resistance.


AWS Class ER312 is a versatile wire with excellent mechanical properties and corrosion resistance. It is widely used in many industries due to its excellent properties and ability to effectively weld austenitic stainless steel, copper, and other metals. AWS Class ER312 provides advantages like easy handling, smooth feeding, and excellent machinability of deposits, making it a popular choice for many applications. Additionally, since it can withstand high temperatures and provide excellent corrosion resistance, AWS Class ER312 wire is perfect for many industrial applications requiring high corrosion resistance.

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