pistetointia

Pistetointia is a Finnish term that translates to "spot welding" in English. It is a resistance welding process used to join two or more metal sheets or workpieces together. In spot welding, the heat necessary to melt the metal is generated by the electrical resistance of the workpiece itself as current flows through it. This current is passed through a set of copper electrodes, which concentrate the current and pressure onto a small spot.

The process begins with the metal pieces being placed between the electrodes. The electrodes then apply pressure to hold the pieces together. An electric current is passed through the electrodes and the metal. The resistance of the metal causes it to heat up rapidly at the point of contact. When the metal reaches its melting point, a small molten pool forms between the sheets. The current is then switched off, and the electrodes maintain pressure while the molten metal cools and solidifies, creating a strong weld spot.

Spot welding is a widely used joining method in various industries, particularly in the automotive sector for vehicle body construction. Its advantages include speed, cost-effectiveness, and the ability to automate the process. It is also used in the manufacturing of appliances, metal furniture, and other products where sheet metal assembly is required. The strength of a spot weld depends on factors such as the thickness and type of metal, the current applied, the welding time, and the electrode pressure.