Welding Metal Structures: MIG/MAG, TIG, or Electrode — How to Choose
From choosing a welding method to weld inspection — how the main welding technologies for metal structures differ.
Why the choice of welding method matters
The welding method directly affects joint strength, weld appearance, production speed, and cost. Not every method suits every metal thickness, steel grade, and setting — shop fabrication versus on-site installation.
MIG/MAG welding (semi-automatic)
Welding with a consumable wire electrode under shielding gas. Delivers high productivity and consistent weld quality, making it the primary method for series production of carbon and low-alloy steel metal structures in shop conditions.
TIG welding
Welding with a non-consumable tungsten electrode under inert gas (argon). Produces the cleanest, most precise weld of any method, but is slower than MIG/MAG. Used where appearance and precision matter: thin metal, critical or decorative components, stainless steel.
Manual (stick) electrode welding
The most versatile and portable method — requires no shielding gas cylinder or delivery equipment. This makes it the primary method for on-site installation of metal structures and field conditions where hauling gas equipment is impractical.
How the welding method is chosen for a specific joint
Key factors: metal thickness and steel grade, strength and appearance requirements for the joint, shop production versus on-site installation, and on-site availability of shielding gas.
Weld quality control
For critical metal structures, visual inspection alone is not enough — ultrasonic testing (per ISO 17640) and radiographic testing (ISO 17636) check for internal weld defects, while visual weld inspection follows ISO 17637. Welders must be certified for the specific methods and joint types they perform.
Need welding for your metal structure project?
UK-ZTO-AN performs MIG/MAG, TIG, semi-automatic, and electrode welding — certified welders, quality control to ISO standards.