CE compliant – Regulation (EU) No. 305/2011
Standard: DIN EN ISO 13918 – Type RD-DUO
Combined material: Steel 4.8 welding tip + stainless steel threaded section
Cold-rolled thread: Tolerance 6g
Reduced shank: Minimum weld bead, approximately 0.5–1 mm larger than the thread
Product description – RD-DUO
The BEARFIX® RD-DUO bimetallic threaded stud is designed for drawn arc stud welding with ceramic ferrule. It combines a weldable steel 4.8 tip with a stainless steel threaded section.
The thread extends almost to the welding tip and the shank is reduced approximately to the thread core diameter. This produces a weld bead only 0.5–1 mm larger than the external thread diameter, making it particularly suitable for restricted spaces or clean finishes.
⚠️ Important: The reduced welding tip lowers bearing strength by approximately 15% compared with MD-DUO. Select the next larger diameter where required.
Main applications
- Marine and offshore construction
- Chemical and process plants
- Food and pharmaceutical industries
- Corrosive environments
- Carbon-steel structures requiring stainless threads
- Restricted spaces requiring a minimal weld bead
Technical advantages
- Bimetallic design
- Cost efficiency
- Minimum weld bead – only 0.5–1 mm larger than the thread
- Cold-rolled thread
- Excellent weldability
Available material combinations
- 78-14: steel 4.8 tip + stainless steel 1.4571 thread
- 78-12: steel 4.8 tip + A2-50 stainless steel thread
Standard dimensions – RD-DUO
| Thread | l2 (mm) | d1 (mm) | d2 (mm) | d3 (mm)* | h (mm)* | 4.8 + 1.4571 article No. | 4.8 + A2-50 article No. | Ceramic ferrule |
|---|---|---|---|---|---|---|---|---|
| M8 | 15–100 | 6.2 | 4 | 7 | 2.5 | 78-14-08-XXX-R | 78-12-08-XXX-R | RF 8 / KSR-F 8 |
| M10 | 20–100 | 7.9 | 5 | 11.5 | 3.5 | 78-14-10-XXX-R | 78-12-10-XXX-R | RF 10 |
| M12 | 20–100 | 9.5 | 6 | 13.5 | 4 | 78-14-12-XXX-R | 78-12-12-XXX-R | RF 12 |
| M16 | 25–100 | 13.2 | 7.5 | 16.8 | 5.8 | 78-14-16-XXX-R | 78-12-16-XXX-R | RF 16 |
| M16 flat form | 25–100 | 13.2 | 11 | 16.1 | 6.5 | 78-14-16-XXX-R | 78-12-16-XXX-R | RF 16 flat |
* d3 and h are approximate. Replace XXX with the required length. Other lengths and threads are available on request.
Standards and certificates
- CE marking according to Regulation (EU) No. 305/2011
- DIN EN ISO 13918 – Type RD-DUO
- DIN EN ISO 14555 – Stud welding
- DIN EN 10204 inspection certificates on request
Return to Bimetallic Threaded Studs.