Lasaco is your solution partner for spot welding technology

For many years, Lasaco has been closely involved in the further development of modern welding technology as the general importer for spot welding technology from Tecna. In the control of automated welding processes, we have made a decisive contribution to the development of today's common industry standards in this field.

Accordingly, our service technicians are particularly familiar with resistance welding technology. In addition to years of practical experience gained through service and repair work, our employees undergo continuous training in order to find a suitable solution for every problem.

Tecna - world market leader in resistance welding technology

Since 1972, the Tecna company has been engaged in the manufacture and sale of spot and projection welders. These are mainly used in car body and vehicle construction to join sheet metal. However, spot welding technology is also established as a standard process in other industries such as the manufacture of household appliances, general sheet metal processing and in workshops.

In addition to the actual spot-welding guns and other equipment, Tecna produces all essential components up to complex control systems, transformers, inverters and much more. Decisive are always the special requirements of the customers, to which existing solutions can be flexibly adapted. Lasaco, as a cooperation partner of Tecna, has a large share in the development of control systems for automated welding processes.

Spot welding fundamentals

This process, also known as resistance welding, is one of the welding techniques that do not require the use of shielding gas. In the spot welding process, two workpieces positioned one above the other are joined by applying a high voltage. The spot heating liquefies the materials very precisely at the desired location. As a result, material distortion is very low compared with continuous welds.

High productivity and operating speed make spot welding the ideal welding method for automating production processes. In body and vehicle manufacturing, virtually all manufacturers use spot welding in high-volume production. Accordingly, the automated spot welding process is also suitable for other industries where similar conditions exist. These include, among others, the electrical industry and all sheet metal processing manufacturing processes.

Resistance spot welding in detail

Resistance spot welding, as the spot welding process is correctly called, is used for spot welding of metal sheets, which can have almost any dimensions. Another particularly interesting aspect is that almost all metals can be joined in a wide variety of combinations. The joining of sheet metals is usually found in car body and vehicle construction, but also in other areas of sheet metal processing and in the electrical industry. In the manufacture of motor windings, relays, circuit breakers and capacitors, the spot welding process has become indispensable in production.

The operating principle is based on the effect of electric current, which is fed to the workpieces via electrodes with pinpoint accuracy. Due to their own electrical resistance, the respective workpieces heat up to the desired welding temperature, at which the surfaces liquefy. The joint is formed directly at the small-area contact point between the electrodes as soon as the melt solidifies or the materials are welded together by diffusion or in solid phase. The actual joint becomes inseparable due to additional high pressure acting between the workpieces. The time required for welding is very short, which is why productivity is correspondingly high.

Resistance projection welding - the other resistance welding technique

In contrast to the spot welding process, resistance projection welding is a technique in which the current density is not determined by the electrodes but by the shape of the respective components. This pressure welding process is used when wires, weld nuts or sheets of different material compositions and dimensions have to be joined together.

Although projection welding machines are similar in design to resistance spot welding technology, the electrodes there serve only to supply current and force, but not to generate the required current density. Closely related to resistance projection welding are processes such as ring edge welding and cross wire welding.

Questions and answers about spot welding

  • What type of current is used in spot welding?

    Usually, alternating current (AC) is used in resistance welding technology, as this can be easily generated from the mains current using suitable transformers.

    If a particularly uniform and at the same time fast energy input is required, direct current (DC) is also occasionally used. However, since direct current generation is technically more complex, this also increases the costs of the process.

  • In which areas is spot welding used?

    The range of applications for spot welding technology is very wide. From sheet metal processing to bodywork and vehicle construction to use in the trades for repairs and maintenance as well as in electronics manufacturing, resistance welding technology is suitable for many areas.

  • What are the advantages of the spot welding process?

    The distortion of components due to heating during welding is significantly lower. In addition, spot welding requires neither filler material nor shielding gas. It is suitable for a wide range of material combinations and is considered to be very energy- and cost-efficient in use. This makes the process ideal for automating production processes.

  • What are the electrodes made of in spot welding?

    Due to the high thermal conductivity and low electrical resistance, electrodes made of low-wear copper alloys are usually used. As a result, the welding heat is primarily generated in the workpiece and not in the electrodes.

  • How does the spot welding technology work?

    Two electrodes are pressed onto the superimposed sheets from both sides. The necessary welding heat is generated by the current flowing into the components via the electrodes. Since the electrical resistance of the sheets is higher than that in the electrodes, the heat is generated precisely between the components.

  • Which materials are suitable for spot welding?

    This welding process can be used to weld a very large number of metals that would otherwise be difficult to combine. These include aluminum, brass, copper, gold, steel, stainless steel, titanium, platinum, iron, silver, bronze, chromium and molybdenum.

How do you find the optimum welding process for your material?

Welding process Material
TIG welding All metals
MAG welding All steels
MIG welding Alloyed steels, non-ferrous metals
Laser welding All steels, light metals, glass
Electrode welding All steels
Resistance welding All metals
Stud welding (tip ignition) Carbon steel, stainless steel, brass
Stud welding (drawn arc) Unalloyed steel, stainless steel

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LASACO's cooperation partners at a glance

Since all customers have their own ideas, wishes and technical requirements for their individual order, we work together with strong partners. This is the only way to provide the required quality and reliability for applications in industry and trade. Here you will find an overview of the renowned manufacturers with whom we cooperate in the field of welding and industrial robot technology as well as other components. Quality is our top priority. Always.