Robotic welding processes compared
Spot, MIG/MAG, TIG and laser: what each process contributes, what it demands from the cell and how to choose with the real part.
The welding process defines the cell, not the other way around. Material, thickness, joint type, finish, speed and volume change the source, torch, fixturing and safety. Comparison uses test pieces and real parts.
Resistance spot welding
Joins sheets by pressure and current at discrete spots. Common in automotive and subassemblies. Gun, transformer, electrodes and maintenance are part of the process; it is not an arc cell.
MIG/MAG
Continuous bead with wire and gas. Versatile for steel, stainless and aluminum, and often the basis of production cells. Edge preparation, gas and transfer define quality.
TIG
Fine control, ideal for thin sections and demanding finishes. It is slower and requires more preparation skill. It is used when quality or material justify the cost.
Laser
High speed and precision, with strict fit-up, safety and material absorption requirements. It is not an option for every shop; it is assessed by part and volume.
Comparison table
The table organizes the first decision; then it is validated with the real part and process.
| Criterion | Spot | MIG/MAG | TIG | Laser |
|---|---|---|---|---|
| Best for | Sheet and subassemblies | Production and continuous beads | Quality and thin sections | Speed and precision |
| Speed | High | High | Medium / low | Very high |
| Fit-up | Tolerant to pressure | Medium | Demanding | Very demanding |
| Consumables | Electrodes | Wire and gas | Rod and gas | Often no filler |
| Cell | Gun and transformer | Source, torch and extraction | Fine control and shielding | Laser safety and fit-up |
How to choose
Compare material, thickness, joint, finish, speed, volume, fit-up and safety. Testing with test pieces and real parts decides; the brochure only guides.
Frequently asked questions
Spot, MIG/MAG, TIG or laser?
It depends on material, thickness, joint, finish, speed, volume and fit-up. The guide table guides; testing with test pieces and real parts decides.
Which one is faster?
Laser and spot are usually faster in their typical cases; MIG/MAG is versatile and TIG prioritizes control. Real speed depends on part and cell.
Which one demands better fit-up?
Laser is the most demanding; TIG also requires careful preparation. Spot tolerates more pressure and MIG/MAG sits in the middle.
Can the process be changed in an existing cell?
Sometimes, but source, torch, fixturing, safety and parameters change. It is assessed as a retrofit, not a simple program change.
How is quality controlled?
With parameters, monitoring, visual inspection and agreed tests. Vision can help, but does not replace code-required testing.
What data is needed to choose?
Material, thickness, joint type, finish, volume, cycle, tolerances, access and safety. Testing with the real part closes the decision.
