How welding robots work and what it requires of the metal fabricator
For many years, robot welding was reserved for large factories with long series, like the car industry. Today you find welding robots also at smaller and medium-sized fabrication businesses because the technology has become cheaper and easier to set up for shorter series. For the metal fabricator, this means that the role often shifts from operating the gun yourself to planning, programming and controlling the robot's work.
A typical welding robot cell consists of the robot arm itself with welding gun one or more positioners that rotate the part so the robot can reach all welds a clamping fixture that holds the part precisely in place each time as well as safety guarding and light curtains that stop the robot if a person comes too close during operation.
The robot's path can be programmed in two ways. In online programming, the robot is manually guided through the movements with a hand control as it learns the positions. In offline programming, the path is created in a simulation program based on a 3D model of the part, after which the program is transferred to the robot — this saves production time because the robot does not have to stand still during the programming itself.
Alongside traditional industrial robots that work behind guards collaborative robots — often called cobots — are gaining ground. They are equipped with sensors that make them stop or reduce power on contact which in some setups makes it possible for humans to work closer to them without full guarding. They are typically used for smaller batches and frequent changeovers where a large industrial robot would be too rigid a solution.
Although the robot handles the gun a robot cell still requires professional insight: someone must choose welding parameters design fixtures programme the path and — not least — check the result and correct when something deviates. The experienced welder who understands what a good weld seam looks like and why it becomes what it does is therefore at least just as important in automated production as in manual welding.
The person operating a welding robot can be qualified according to ISO 14732 on the qualification of operators for mechanised and automatic welding. The latest edition came out in June 2025.
Robot welding is best suited to uniform parts in reasonable quantities where the clamping is stable and repeatable. Single pieces, very varied items and repair work in the field will still require a human welder who can adapt as they go. Most companies therefore end up with a combination where the robot takes the repetitive tasks and the manual welder takes what requires judgment.