Electrode and Wire Classifications in Arc Welding: A Technical Overview

Aygün Karaköse

1 Jul, 2025 09:07 AM

arc welding processes such as SMAW (Shielded Metal Arc Welding), MIG (Metal Inert Gas), TIG (Tungsten Inert Gas), and MAG (Metal Active Gas), electrodes and wires are classified and coded according to international standards. These designations help welders select the appropriate consumables to ensure weld quality and suitability for specific applications. This article explains common electrode and wire classification systems with representative examples and their meanings.

1. Step 1: SMAW (Shielded Metal Arc Welding) Electrode Classification

   The most widely used standard is AWS A5.1 (American Welding Society). For example, E7018:

   
   

   • E: Electrode
   • 70: Minimum tensile strength in ksi (70 ksi ≈ 480 MPa)
   • 1: Welding position (1 = all positions, 2 = flat and horizontal only)
   • 8: Electrode coating and current type code (8 = low hydrogen, usable with AC or DC current)

   Example: E6010

   • E: Electrode
   • 60: Minimum tensile strength 60 ksi
   • 1: All positions
   • 0: Cellulose-type coating, deep penetration, typically DC+

   
   

2. Step 2: MIG (GMAW – Gas Metal Arc Welding) Wire Classification

   MIG wires follow the AWS A5.18 standard. Example: ER70S-6

   • ER: Electrode Rod (welding wire)
   • 70: Minimum tensile strength in ksi
   • S: Solid wire
   • 6: Chemical composition code indicating higher manganese and silicon content, which improves deoxidation

   
   

3. Step 3: TIG (GTAW – Gas Tungsten Arc Welding) Electrode Classification

   G electrodes are tungsten-based and classified under ASTM E 394.

   Example: EWTh-2

   • E: Electrode
   • W: Tungsten
   • Th: Thorium oxide (Thoria) doping
   • 2: Percentage of thorium oxide (2%)

   Other variants include:

   • EWCe-2: Cerium oxide-doped tungsten electrode
   • EWLa-1.5: Lanthanum oxide-doped tungsten electrode

   
   

4. Step 4: MAG (Metal Active Gas) Welding Wire Classification

   MAG wires also use AWS A5.18 standards. Example: G3Si1

   • G: Gas-shielded wire
   • 3: Minimum tensile strength (ksi)
   • Si: Silicon as the main alloying element
   • 1: Classification number indicating standard silicon content

   
   

5. Step 5: Summary Table

   Welding Process Example Meaning

   SMAWE 701870 ksi strength, all positions, low hydrogen coating

   MIG ER70S-670 ksi strength, solid wire, high Mn and Si content

   TIG EWTh-2 Tungsten electrode with 2% thorium oxide doping

   MAG 3Si1 Gas-shielded wire, 70 ksi, silicon alloyed