The FELDER “UNIVERSAL” hard soldering paste is a high-performance brazing flux paste formulated with boron compounds.
It is optimized for hard soldering and welding of copper, copper alloys (including brass), gray cast iron, malleable cast iron, and steel.
With a working temperature range of 750–1100 °C, this flux paste meets the highest soldering requirements in industry and trade. Its non-corrosive residues can remain on the joint or be removed mechanically or with water.
The paste is classified as Type FH 21 according to DIN EN 1045 and complies with RoHS Directive 2011/65/EU, making it safe for distribution through hardware stores and suitable for professional and DIY use.
TECHNICAL DETAILS:
| Specification | Details |
| Brand | FELDER |
| Type | Hard soldering flux paste (FH 21) |
| Activity Range | 750–1100 °C |
| Form | Pasty |
| Color | White |
| Residues | Non-corrosive, removable if necessary |
| Applications | Brazing copper, copper alloys, cast iron, steel; welding brass |
| Compatible Rods/Wires | Silver hard solders (Ag 212, Ag 225, Ag 401), Brass Cu 670, Cu 681, Nickel silver Cu 773, Copper wires Cu 99.9, Cu 1898, Cu 6560, Cu 1897 |
| Compliance | DIN EN 1045, EN ISO 17672, EN ISO 24373, RoHS 2011/65/EU |
| Storage | Tightly closed, protected from humidity, sunlight, and heat |
| Shelf Life | 24 months from production date |
| Packaging | 250 g bottle |
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