PT or CD1 studs are fastening elements specially designed for capacitor discharge welding.
- PT is the designation according to DIN EN ISO 13918.
- CD1 is the technical/commercial designation used for capacitor discharge welding.
The CD1 designation refers to the PT-type threaded stud according to DIN EN ISO 13918. Thanks to their calibrated ignition tip and cold-formed flange, these studs provide a stable and repeatable weld, even on thin sheet metal where other welding processes could cause distortion or leave marks on the reverse side of the sheet.
Capacitor discharge welding makes it possible to weld studs onto metal sheets without drilling, creating a fast, strong joint with minimal thermal distortion. The discharge process takes only 2 or 3 milliseconds, enabling very fast production cycles and clean finishes. This is particularly important in sectors such as automotive manufacturing, HVAC, electrical cabinets and general industrial production.
What does CD1 stud mean?
Capacitor discharge welding systems use different types of studs depending on their geometry and application.
| Designation | Stud type |
|---|---|
| CD1 | Threaded stud (PT) |
| CD2 | Unthreaded or plain stud (UT) |
| CD6 | Internally threaded stud (IT) |
The CD1 model is the most widely used when a permanent threaded fastening is required on sheet metal.
Features of PT / CD1 studs
Designed to ensure fast, accurate and strong capacitor discharge welding, PT CD1 studs feature an external metric thread, a calibrated ignition tip and a cold-formed flange that improves arc stability and increases the joining surface.
The stud flange plays an important role by preventing displacement of the electric arc and increasing the joining surface.
PT or CD1 studs are ideal for welding onto thin sheet metal because they minimise distortion and marks on the workpiece while providing high mechanical strength.
Available standard sizes
The most common models are manufactured from M3 to M10.
| Thread | Available length |
|---|---|
| M3 | 6 – 30 mm |
| M4 | 6 – 40 mm |
| M5 | 6 – 45 mm |
| M6 | 8 – 60 mm |
| M8 | 10 – 60 mm |
| M10 | 12 – 60 mm |
Special sizes can also be manufactured to drawing.
Available materials
PT or CD1 studs can be supplied in different materials according to the working environment and the required mechanical strength or corrosion resistance. All materials comply with DIN EN ISO 13918 and DIN EN ISO 14555.
| Material | Features |
|---|---|
| Copper-plated 4.8 steel | Excellent weldability and high strength |
| A2-50 stainless steel | Good corrosion resistance |
| 1.4571 stainless steel | Chemical applications or aggressive environments |
| AlMg3 aluminium | Lightweight with good conductivity |
| CuZn37 brass | Special technical applications |
Do you need PT or CD1 studs for capacitor discharge welding?
You can find them directly in our online store together with a wide range of industrial studs, accessories and consumables. Click the “Online store” button to view all available references, with immediate delivery and specialist technical advice.