Welding Methods Comparison Guide for Fabrication Sourcing
Compare welding methods available from Chinese manufacturers: TIG, MIG, stick, spot, laser, and submerged arc welding. Process selection guide for fabrication sourcing.
Welding is a core fabrication process for metal products. Chinese factories offer the full range of welding methods, from manual to fully automated. Choosing the right process affects cost, quality, appearance, and lead time.
TIG Welding (GTAW)
Tungsten Inert Gas
Uses a non-consumable tungsten electrode with filler rod. Produces the highest quality, cleanest welds.
- Materials: Stainless steel, aluminum, titanium, copper, magnesium
- Thickness: 0.5-6mm (ideal for thin materials)
- Speed: Slow — most manual of all processes
- Cost: $$ — skilled welders required
- Best for: Sanitary tubing (food/pharma), aerospace components, thin-wall structures, cosmetic welds that require no grinding
MIG/MAG Welding (GMAW)
Metal Inert/Active Gas
Continuous wire feed through a welding gun. Semi-automatic to fully automatic. Most common production welding process in China.
- Materials: Carbon steel, stainless steel, aluminum
- Thickness: 1.5-25mm
- Speed: Fast — high deposition rate
- Cost: $ — most economical for volume production
- Best for: Structural steel, frames, enclosures, automotive body panels, general fabrication
Stick Welding (SMAW)
Shielded Metal Arc
Manual process using flux-coated electrode. Oldest and most forgiving method. Excellent for outdoor and field work.
- Materials: Carbon steel, stainless steel, cast iron
- Thickness: 3mm and above
- Speed: Moderate — requires frequent electrode changes
- Cost: $ — low equipment cost
- Best for: Heavy steel structures, field repairs, shipbuilding, construction sites
Spot Welding (Resistance)
Resistance Spot Welding
Uses electrical current and pressure between two copper electrodes to fuse overlapping metal sheets.
- Materials: Low-carbon steel, stainless steel, aluminum (difficult)
- Thickness: 0.5-3mm per sheet
- Speed: Very fast (0.2-1 second per spot)
- Cost: $$ — robotic systems expensive but low per-weld cost
- Best for: Automotive body assembly, sheet metal enclosures, electronics chassis, battery pack assembly
Laser Welding
Laser Beam Welding
High-precision welding using focused laser beam. Minimal heat-affected zone, minimal distortion.
- Materials: Stainless steel, carbon steel, aluminum, titanium, dissimilar metals
- Thickness: 0.1-6mm
- Speed: Very fast — up to 5-10 m/min
- Cost: $$$ — high equipment investment
- Best for: Precision components, hermetic seals, battery sealing, medical devices, thin-walled parts needing minimal deformation
Submerged Arc Welding (SAW)
Submerged Arc
Arc is submerged under granular flux. Highest deposition rate of all arc welding processes. Highly automated.
- Materials: Carbon steel, low-alloy steel, stainless steel
- Thickness: 5mm and above (no upper limit)
- Speed: Very high — multiple welding heads possible
- Cost: $$ — high efficiency but requires setup
- Best for: Heavy plates, pressure vessels, ship hulls, structural beams, pipe welding
Method Comparison
| Process | Speed | Quality | Thickness | Automation | Relative Cost |
|---|
| TIG | Slow | Excellent | 0.5-6mm | Difficult | $$$ |
| MIG/MAG | Fast | Good | 1.5-25mm | Easy | $ |
| Stick | Moderate | Moderate | 3mm+ | No | $ |
| Spot | Very fast | Good | 0.5-3mm | Yes | $$ (robotic) |
| Laser | Very fast | Excellent | 0.1-6mm | Yes | $$$$ |
| Submerged Arc | Very high | Excellent | 5mm+ | Yes | $$ |
Quality & Inspection
Welding quality in Chinese factories varies widely. Request these checks:
- Visual inspection: Check for cracks, undercut, porosity, spatter, proper bead profile
- Dye penetrant (PT): Surface crack detection. Low cost, fast.
- Radiographic (RT/X-ray): Internal defect detection. Required for pressure vessels and critical structures.
- Ultrasonic (UT): Internal defect detection. Cheaper and faster than RT.
- Mechanical tests: Tensile strength, bend test, hardness test on weld coupons.
- Welder certification: Request copies of welder certifications (ISO 9606 or equivalent).
Most medium-to-large Chinese fabrication shops have NDT (Non-Destructive Testing) equipment or access to third-party testing labs.