Pin welding with tip ignition is a capacitor discharge welding process in which a cylindrical ignition tip triggers the arc. It is typically used for pins up to approximately 8 mm in diameter and operates with very short welding times (approx. 1–3 ms) – ideal for thin sheets and applications requiring minimal heat input.
Key facts at a glance
Highlights on this welding technology
| Feature | Reference Value / Note |
|---|---|
| Stud Ø | up to approx. 8 mm |
| Peak Current | up to approx. 10.000 A |
| Welding Time | approx. 1–3 ms |
| Power Source | Capacitor battery |
| Polarity (typical) | Negative pole at stud |
| Ignition Aid | Cylindrical tip |
| Quality Check | Test weld + Visual inspection; Additional tests depending on application |
Details of our welding technology
The process “stud welding with tip ignition” is used for studs up to a diameter of approximately 8 mm. Studs, having a small cylindric tip, are in use. A capacitor battery serves as power source. The maximum current can reach 10.000 A; the welding time is between 1 and 3 ms.
The capacitor battery will be loaded up to a defined voltage. In general, the negative pole will be connected to the stud. The studs with its precisely dimensioned cylindric tip will be moved to the workpiece. With the contact of the tip to the workpiece, the circuit closes. The quickly increasing current is melting the welding tip and with it, the arc will ignite. Stud and workpiece are melting. By the contact between stud and workpiece, the arc will lapse, the melting zones join tightly and solidify. The remaining energy of the capacitor will unload by a short-circuit.
Stud welding with tip ignition comprises two different processes.
As discribed above, in the course of the process “welding with gap” the stud will be accelerated to a certain speed. The movement will not be delayed by the ignition process.
In the course of the process “welding with contact”, spring force will move the stud to the workpiece. Caused by the increasing current, the welding tip will melt promptly and ignite the arc. Now the stud moves towards the workpiece and melts. As the stud must be accelerated from static condition, the result is a longer welding time, compared to the process “welding with gap”.
The extremely short welding process can only be followed by the aid of oscillograph curves. The measuring instruments, which are nowadays availble, are capable to store the process and thus allow an exact evaluation of the cycle.
Schritt 1
Start
Schritt 2
Electric arc burning
Schritt 3
Plunge
Schritt 4
Finished weld
Watch the KÖCO tip ignition process in action – precise, fast and ideal for thin sheet metal.
Frequently asked questions about stud welding with tip ignition
What is the difference between tip ignition and stroke ignition?
Tip ignition works by means of capacitor discharge and involves very short durations in the millisecond range. Stroke ignition uses a stroke mechanism and longer process times; it is suitable for larger diameters and more robust applications. The choice depends primarily on sheet thickness, pin diameter and quality requirements.
How can I tell whether ‘gap’ or ‘contact’ is the right option?
If the process is designed for reproducible movement and a defined contact distance, ‘gap’ is often chosen (faster process). ‘Contact’ is an alternative when the ignition tip is held in place by spring force – in this case, the welding time is typically longer. In both cases, parameters should be validated by means of test welding.
What role does surface preparation play?
Very short-duration processes are sensitive to oil, coatings and oxide. A clean, metallic surface improves ignition and reduces failures (e.g. ignition problems or incomplete welds). Before series production starts: clean, test, document.
How can I monitor the process when everything happens so quickly?
The process is so brief that it can practically only be assessed in detail using measuring and recording equipment (e.g. oscillograms). Modern equipment can store the sequence; in practice, it is also advisable to carry out consistent test welds with visual inspection.
