Welding is one of the most fundamental joining processes in manufacturing. With multiple methods available, selecting the right one depends on material type, thickness, production volume, quality requirements, and cost. This guide covers the most commonly used industrial welding processes.
How it works: A non-consumable tungsten electrode produces the arc, while an inert gas (usually argon) shields the weld pool. Filler metal can be added manually or omitted for autogenous welds.
| Parameter | Specification |
|---|---|
| Materials | Stainless steel, aluminum, titanium, copper alloys, magnesium |
| Thickness range | 0.5 – 6 mm (sheet metal to moderate sections) |
| Speed | Slow — 50–150 mm/min (handheld) |
| Quality | Excellent — minimal spatter, smooth finish, narrow HAZ |
| Cost | Moderate equipment, high operator skill required |
| Automation | Orbital TIG available for tube/pipe welding |
Best for: Thin-section stainless steel, aluminum fabrication, aerospace components, sanitary tubing (food/pharma), root passes for pipe welding.
Limitations: Slow deposition rate, sensitive to draft/air movement, requires highly skilled welders. Operator training: 3–6 months minimum for competent work.
How it works: A continuously fed wire electrode serves as both filler metal and arc source. Shielding gas is supplied through the welding gun. MIG uses inert gas (argon); MAG uses active gas (CO₂ or mix).
| Parameter | Specification |
|---|---|
| Materials | Carbon steel, low-alloy steel, stainless steel, aluminum (with proper setup) |
| Thickness range | 1 – 25 mm (most productive in 3–20 mm range) |
| Speed | Fast — 3–5× faster than TIG, 200–600 mm/min |
| Quality | Good — more spatter than TIG, acceptable for most applications |
| Cost | Low equipment cost, easy to learn, higher consumable usage |
| Automation | Excellent — robotic MIG is the most common automated welding process |
Best for: Structural steel fabrication, automotive body panels, shipbuilding, heavy equipment, general manufacturing — the "workhorse" of welding.
Limitations: More spatter than TIG, outdoor use requires wind protection, limited positional welding without pulsed capability.
How it works: A high-energy laser beam (fiber, CO₂, or diode) melts the base material, typically without filler metal. Keyhole mode achieves deep penetration with minimal heat input.
| Parameter | Specification |
|---|---|
| Materials | Steel, stainless, aluminum, titanium, dissimilar metals (with limitations) |
| Thickness range | 0.1 – 6 mm (single pass); up to 15 mm with keyhole mode |
| Speed | Very fast — up to 5–10 m/min for thin sheets |
| Quality | Excellent — minimal HAZ, low distortion, clean appearance |
| Cost | High capital investment ($100k–$500k+), low per-part cost at volume |
| Automation | Fully automated — robot or CNC-controlled, often integrated into production lines |
Best for: High-volume automotive battery packs, electronic enclosures, medical devices, thin-section precision parts, hermetic sealing.
Limitations: High initial investment, tight joint fit-up required (gap < 10% of material thickness), safety enclosure needed, limited thick-section capability.
How it works: A rotating tool generates frictional heat and stirs the material in a plastic state — no melting, no filler, no shielding gas.
| Parameter | Specification |
|---|---|
| Materials | Aluminum, magnesium, copper, titanium (harder materials challenging) |
| Thickness range | 1 – 50+ mm (depending on machine capacity) |
| Speed | Moderate — 100–500 mm/min |
| Quality | Excellent — no solidification defects, low distortion, superior mechanical properties |
| Cost | High equipment cost, no consumables (no wire/gas), specialized tooling required |
| Automation | Fully automatable — CNC milling machines or dedicated FSW machines |
Best for: Large aluminum panels (shipbuilding, rail cars), aerospace fuel tanks, EV battery trays, heat exchangers.
Limitations: Requires high clamping force, keyhole at exit, limited to relatively simple joint geometries (butt, lap), expensive tool wear on high-melting-point materials.
How it works: A consumable electrode coated with flux provides both filler metal and shielding gas through flux decomposition. The oldest and most portable welding process.
| Parameter | Specification |
|---|---|
| Materials | Carbon steel, stainless, cast iron, hardfacing alloys |
| Thickness range | 3 mm – unlimited (structural sections) |
| Speed | Slow — frequent electrode changes, slag removal required |
| Quality | Good — slag inclusion risk, acceptable for structural work |
| Cost | Lowest equipment cost — basic machines under $500 |
| Portability | Excellent — no gas bottle needed, works outdoors in wind |
Best for: Field welding, construction sites, repair and maintenance, heavy structural steel, pipe welding (root + fill).
Limitations: Low productivity (slag removal between passes), requires high operator skill for quality results, not suitable for thin materials or automated production.
How it works: A granular flux blanket completely covers the arc, eliminating spatter and UV radiation. Wire feed is continuous.
Best for: Heavy plate fabrication (shipbuilding, pressure vessels, structural beams), longitudinal seam welding of pipe, large storage tanks.
Key advantage: Highest deposition rate of any arc welding process — up to 45 kg/hour with tandem wire setups. 100% duty cycle possible.
| Requirement | Best Choice | Runner-up |
|---|---|---|
| Highest quality (thin materials) | TIG (GTAW) | Laser welding |
| Best productivity (manual) | MIG/MAG (GMAW) | Flux-cored (FCAW) |
| Best for automation | MIG robotic | Laser welding |
| Field / outdoor work | Stick (SMAW) | Self-shielded FCAW |
| Thick plate (50+ mm) | SAW | Electroslag (ESW) |
| Aluminum joining | MIG pulsed | FSW |
| Dissimilar metals | Laser / EBW | FSW (if solid-state works) |
| Lowest distortion | Laser / EBW | TIG (with careful fixturing) |
| Lowest equipment cost | Stick (SMAW) | MIG (basic setup) |
| Lowest per-part cost (volume) | Robotic MIG | Laser (at very high volume) |
| Defect | Cause | Prevention |
|---|---|---|
| Porosity | Contaminated surface, inadequate gas shielding, moisture in flux | Clean base metal, check gas flow rate (15–25 L/min), dry consumables |
| Cracking | High restraint, hydrogen embrittlement, incorrect filler metal | Preheat (100–200°C for medium-carbon steels), use low-hydrogen process, proper joint design |
| Undercut | Excessive current, travel speed too fast, incorrect torch angle | Reduce current, slow down, maintain proper torch angle (15–20° for MIG) |
| Incomplete fusion | Low heat input, incorrect electrode angle, dirty surface | Increase current/weld speed ratio, ensure proper cleaning between passes |
| Spatter (excessive) | Incorrect voltage/current settings, wrong shielding gas mix | Use pulsed MIG for aluminum, optimize parameters, anti-spatter spray |
Last updated: June 2026 — MFGABC Manufacturing Knowledge Base