Basics & process choice
What is welding and how does it work?
Quick answer
Welding joins metals by melting them together — usually with an electric arc around 6,000°C that fuses the parent metals and a filler into one continuous piece. Unlike brazing or soldering, the base metal itself melts, which is what makes a weld as strong as the parts it joins.
The core physics
An arc jumps a small gap between electrode and work, converting electrical energy into intense localized heat. The molten pool is shielded from air by gas or flux — oxygen and nitrogen in air would otherwise make the weld brittle and porous. As the arc moves on, the pool freezes into a fused joint.
The family tree
- Arc welding: MIG, TIG, stick, flux-core — the overwhelming majority of work
- Laser and electron beam: precision and production welding
- Resistance: spot and seam welding — clamped, no filler
- Gas and forge: oxy-acetylene — mostly cutting and legacy repair today