Drawn arc stud welding with shielding gas is an arc welding process in which studs (typically Ø 3–12 mm, sometimes up to 16 mm) are welded to a base material. Instead of a ceramic ring, a shielding gas atmosphere within the gas bell protects the molten pool from reacting with the ambient air (pre-flow time, sealing and gas quality are critical to the process).
Key facts at a glance
Key Values & Requirements (Reference Values)
| Feature | Reference Value / Note |
|---|---|
| Stud Ø | 3–12 mm (up to 16 mm) |
| Polarity (typical) | Positive pole at workpiece |
| Protection Principle | Gas shroud instead of ceramic ferrule |
| Pre-flow Time | Fill gas shroud with shielding gas before ignition (adjustable) |
| Seal at Top | Seal gas shroud at stud holder via rubber collar |
| Gas Outlet at Bottom | Gas must exit laterally at workpiece through slots |
Details of our welding technology
The process „drawn arc stud welding with shielding gas“ is used for welding studs of a diameter of 3 to 12 mm ( 16mm). In general, the positive pole of the power-source is connected to the workpiece. The stud will be inserted into the chuck of the stud welding gun and positioned onto the workpiece, possibly by adding a ceramic ferrule.
Initiating the welding process: by means of a lifting mechanism, the stud will be lifted and at first an auxiliary arc (pilot arc) of a low current will be drawn. Then the main arc will be drawn between the tip of the stud and the workpiece. The main arc of a high amperage must be adjusted to the diameter of the stud. The cross sectional area of the stud and the opposite workpiece a partially melting.
After the lapse of the adjusted welding time, the stud is moved towards the work piece and both melting zones join tightly. The power-source turns off, the melting zone solidifies and cools down.
In order to obtain a good gas-protection, an adequate appliance is indispensable. At the upper part of the chuck, the gas chamber should be sealed by means of a rubber sleeve.
Down at the workpiece, lateral slotts are required to allow the gas to escape.
The use of appropriate shielding gas is of great importance: mild steel and stainless steel: 82% Ar and 18% Co2, for aluminium; pure Argon or Ar and He.
Step 1
The stud is placed against the workpiece.
Step 2
The stud is lifted off, while current is flowing, thus creating an arc.
Step 3
The arc melts the surfaces of stud and workpiece.
Step 4
The stud is plunged into the weld pool.
Step 5
The stud is plunged into the weld pool.
See the process in action
This video takes you through drawn arc stud welding with shielding gas – step by step, straight from practice, including the gas shroud, pre-flow time and the interaction of all components.
Important: Shielding gas and ceramic ring pins are not interchangeable
- The pins differ in terms of their ignition tip geometry.
- Using the wrong combination (e.g. ceramic ring pins in an inert gas process) can lead to welding defects.
- When selecting a product, always take the process type (ceramic ring vs. inert gas) into account.
Frequently asked questions about stud welding with shielding gas
For which stud diameters is the shielding gas process suitable?
Typically, spark ignition with shielding gas is used for studs with a diameter of 3–12 mm, and in some cases up to 16 mm – depending on the application and setup.
What is a gas bell and why is it important?
The gas bell replaces the ceramic ring holder on the gun. Before ignition, a pre-flow time fills the bell with shielding gas so that the molten metal reacts less with the ambient air.
What does ‘pre-flow time’ mean?
The pre-flow time is the presettable duration during which shielding gas flows into the gas bell before the actual welding process begins. It is important to ensure that the shielding gas atmosphere is already stable when the arc is struck.
Which shielding gases are recommended?
For steel and stainless steel, a mixture of 82% argon and 18% CO₂ is recommended. For aluminium, pure argon or argon and helium is recommended.
What do I need to bear in mind regarding sealing?
For effective gas protection, the gas bell must be sealed at the top of the bolt holder using a rubber sleeve. At the bottom of the workpiece, the gas must be able to escape sideways through slits.
Can I also weld ceramic ring studs using shielding gas?
No. Shielding gas studs and ceramic ring studs differ in particular at the ignition tip and are not interchangeable. An incorrect combination can lead to welding defects.
