Type US unthreaded studs according to DIN EN ISO 13918 are the ideal solution for non-threaded fastenings using short-cycle welding, providing a base for clips, clamps and other fastening elements.
Unthreaded studs for short-cycle welding (type US) are cylindrical, threadless elements welded to metal surfaces to act as pivots, stops or fastening bases.
Made of grade 4.8 steel with a copper coating, A2-50 stainless steel or 1.4571 stainless steel, they feature a formed flange that improves joint strength and prevents the electric arc from wandering. They are available in diameters from 3 to 8 mm and l1 lengths from 6 to 60 mm, and are compatible with PHM-10, GD 12sc and PHM-1A welding guns.
1. What are unthreaded studs for short-cycle welding?
Type US unthreaded studs are cylindrical threadless fastening elements designed specifically for the short-cycle welding process. They are used where an anchoring point or projection is required on the base sheet but no thread is needed.
Once welded, these studs can accept clips, clamps, spring clips or quick-fastening systems that are pressed or snapped onto them. They can also be used as stops, guides or pivot pins.
2. Technical specifications
Available materials
| Material | Tensile strength (Rm) | Yield strength (Re) | Elongation |
|---|---|---|---|
| Grade 4.8 steel (copper-plated) | ≥ 420 N/mm² | ≥ 340 N/mm² | ≥ 14% |
| A2-50 stainless steel | ≥ 500 N/mm² | ≥ 210 N/mm² (Rp0.2) | ≥ 0.6 d |
| 1.4571 stainless steel | ≥ 500 N/mm² | ≥ 210 N/mm² (Rp0.2) | ≥ 0.6 d |
Flange and geometry
- Cold-formed flange: Larger in diameter than the shank, increasing the welding area
- Conical welding surface: Calibrated to initiate the arc precisely
- Surface protection: 4–8 μm electrolytic copper coating (grade 4.8 steel)
3. Dimension table – Type US unthreaded studs
| Diameter d1 (mm) ±0.1 | l1 (mm) +0.6 | d2 (mm) ±0.2 | h1 (mm) | Grade 4.8 steel item no. | A2-50 item no. | 1.4571 item no. |
|---|---|---|---|---|---|---|
| 3 | 6-30 | 4 | 0.7-1.4 | 27-03-XXX | 28-03-XXX | 281-03-XXX |
| 4 | 6-40 | 5 | 0.7-1.4 | 27-04-XXX | 28-04-XXX | 281-04-XXX |
| 5 | 6-45 | 6 | 0.7-1.4 | 27-05-XXX | 28-05-XXX | 281-05-XXX |
| 6 | 8-60 | 7 | 0.7-1.4 | 27-06-XXX | 28-06-XXX | 281-06-XXX |
| 7.1 | 10-60 | 9 | 0.8-1.4 | 27-07-XXX | 28-07-XXX | 281-07-XXX |
| 8 | 15-60 | 9 | 0.8-1.4 | 27-08-XXX | 28-08-XXX | 281-08-XXX |
Note: Replace “XXX” with the l1 length (example: 27-05-030 for ø5 × 30 mm). l2 (length after welding) depends on l1 and the welding energy.
4. Welding-gun compatibility
| Diameter (d1) | l2 (projected length) | Chuck / nut (item no.) |
|---|---|---|
| 3 mm | l2 ≤ 40 / l2 > 40 | 82-50-003 |
| 4 mm | l2 ≤ 40 / l2 > 40 | 82-50-004 |
| 5 mm | l2 ≤ 40 / l2 > 40 | 82-50-005 |
| 6 mm | l2 ≤ 40 / l2 > 40 | 82-50-006 |
| 7.1 mm | l2 ≤ 40 / l2 > 40 | – / – |
| 8 mm | l2 ≤ 40 / l2 > 40 | 82-50-008 |
Compatible welding guns: PHM-10, GD 12sc, PHM-1A
5. Typical applications
- Industrial insulation: Base for clips used to secure insulation blankets
- Automotive industry: Pivots, stops and guides on panels
- Domestic appliances: Anchoring points for cable clamps
- Metal construction: Connectors for quick-fastening systems
- Industrial machinery: Travel stops and positioning elements
6. Advantages of US unthreaded studs over other solutions
- No drilling: Eliminates the need to drill the sheet metal
- Versatile: Accept multiple fastening systems (clips, spring clips and clamps)
- Strong: The flange provides high mechanical strength
- Fast: Millisecond welding cycle
- Clean surface: No marks on the reverse side of the sheet
7. Compatible fastening systems
Type US unthreaded studs provide the ideal base for the following fastening systems, also available in our catalogue:
- Type R clips: Metal split rings (zinc-plated or stainless steel) for 2, 3, 4 and 5 mm diameters
- Type W clips: With a white or black plastic cap, for 2 and 3 mm diameters
- Spring clamps: For securing pipes and cables
- Metal spring clips: For securing insulation blankets
8. Practical recommendations
- Select the stud diameter according to the expected mechanical load
- For insulation applications, use unthreaded studs as a base for type R or W clips
- Check that the base material is compatible with the stud material
- Keep surfaces clean before welding
- For corrosive environments, choose A2-50 or 1.4571 stainless steel