Sn99,3Cu0,7 SW26

The most cost-effective alternative to lead-containing solders, for professional and amateur use.

Alloy designation according to ISO 9453: Sn99,3Cu0,7 (401)
Product form: cored solder wire
Flux designation: SW26

1. General characteristics

The lead-free solder alloy Sn99,3Cu0,7 is manufactured by Cynel-Unipress in the first smelting of tin and copper. Its chemical composition complies with ISO 9453. Sn99,3Cu0,7 is the most cost-effective alternative to lead-containing solders. It does not contain silver. Alloy is designed for soldering in lead-free technology. It meets the requirements of the RoHS directive. It can be sold on the consumer market and also used by private individuals outside of professional applications.

2. Chemical composition [%]

Sn	Cu	Bi	Sb	Ag	Cd	Au	In	Pb	Al	As	Fe	Ni	Zn	other
rest	0,5 - 0,9	0,1	0,1	0,1	0,002	0,05	0,1	0,07	0,001	0,03	0,02	0,01	0,001	-

3. Physical characteristics

Melting point (solidus/liquidus)	227°C (eutectic alloy)
Specific weight	7,31 g/cm³
Resistivity	0,126 μΩ•m
Thermal conductivity	66 W/m•K
Tensile strength at break	300 kg/cm²
Elongation at break	21%
Hardness	9 HB
Recommended soldering temperature (tip)	320 - 360°C (for nickel plated elements up to 400 °C)

4. SW26 flux

Halide flux based on modified rosin. It provides very good solderability in popular applications in all branches of industry, as well as in hobby applications. The flux works on most metal surfaces except aluminum, its alloys and stainless steel. Flux residues after soldering do not have to be removed and may remain on the soldered surface. Alcohol-based solvents are recommended for washing up the residues.

Designation according to DIN 8511	SW26
Designation according to ISO 9454-1	1.1.2
Designation according to J-STD-004	ROL1
Standard flux contents	2,2% ± 0,2% in Sn99,3Cu0,7 and Sn60Pb38Cu2 alloys 2,5% ± 0,2% in Sn60Pb40, Sn63Pb37 and Sn62Pb36Ag2 alloys other flux contents from 0.8% to 3.5% are negotiable
Halide content	0,5%
Acid number	180mg KOH/g
Copper mirror test	passed (in accordance with J-STD-004 IPC-TM-650 2.3.32D)
Corrosiveness	noncorrosive

5. Other information

Available diameters [mm]	0,25 • 0,38 • 0,50 • 0,56 • 0,70 • 0,80 • 0,90 • 1,00 • 1,20 • 1,50 • 2,00 • 2,50 • 3,00 • 4,00 Other wire diameters possible to be agreed.
Spools and packaging	Spools 100 g - carton box of 30 pcs Spools 250 g - carton box of 5 kg Spools 500 g - carton box of 5 kg Spools 1 kg - carton box of 10 kg Other spool sizes possible to be agreed.
Expiry date	5 full years from the end of the year of production given in the product batch number. E.g.: batch no. 21112233 = year of manufacture 2022, validity until the end of 2027.
Markings	Spools and carton boxes marked with alloy, flux type, percentage content of flux, diameter, weight and batch number.
Storage	Store at room temperature in a dry place out of reach of children.

Files to download:

Technical data sheet - TDS

Safety data sheet - SDS

Physical, mechanical and chemical properties available in the TDS (download above).

The subject of the specification described above complies with the Directive of the European Parliament and of the Council (so-called RoHS) 2011/65/EU of June 8, 2011, as amended, on the restriction of the use of certain hazardous substances in electrical and electronic equipment.