Harris L-CuP6 Round Phosphor Copper Brazing Rod Ø2x500 mm

Harris L-CuP6 round phosphor copper brazing rod comes as rods of Ø2 mm diameter and 500 mm length in a 1 kg pack. It is labeled Harris P6 on the box and is known on the market as Harris Euro L-CuP6. It is a silver-free (0% silver) brazing filler rod consisting of approximately 94% copper and 6% phosphorus. It is used in refrigeration and air conditioning installations for copper-to-copper tube brazing without flux.

L-CuP6 Rod Requiring No Flux for Copper-to-Copper Brazing

The phosphorus in the alloy dissolves the oxide on the copper surface by itself at brazing temperature. Therefore, when joining copper tube to copper tube or to a copper elbow, there is no need to apply flux separately. Split air conditioner copper lines, condensing unit pipe connections, and repairs of copper-tube evaporators and condensers are typical applications.

Technical Specifications

• Brand: Harris (Lincoln Electric)
• Alloy: L-CuP6 phosphor copper, approx. 94% Cu / 6% P
• Silver content: 0% (silver-free)
• Standards: DIN 8513 L-CuP6 · EN 1044 CP 203 · ISO 17672 CuP 179
• Rod form: Round
• Size: Ø2 mm diameter, 500 mm length
• Cross-sectional area: approx. 3.14 mm²
• Melting range: 710 – 890 °C
• Working temperature: 760 °C
• Density: 8.1 g/cm³
• Flux: Not required for copper-to-copper · required for copper-to-brass and copper-to-bronze
• Sales unit: 1 kg

Difference Between Square and Round Rod

Square and round L-CuP6 rods are the same alloy; the difference is in the cross-section of the rod. The cross-sectional area of a 2x2 mm square rod is 4 mm², while that of a Ø2 mm round rod is approximately 3.14 mm². For the same length, the square rod carries approximately 27% more filler material; in the same 1 kg, on the other hand, you get more rods with the round type. Thanks to its thinner cross-section, the round rod melts quickly; it allows more controlled feeding of the rod on small-diameter tubes and in fine work.

L-CuP6 or L-CuP7?

As the phosphorus content increases, the alloy becomes more fluid. L-CuP7 has a melting range of 710 – 820 °C; in narrow, well-fitted joints it spreads easily into the joint by capillary action. L-CuP6 has a wider melting range and flows more sluggishly. This property makes the job easier when filling joints that are not fully seated and when brazing in vertical or overhead positions.

Application Notes

• Preparation: The tube end is cleaned, deburred and fully inserted into the fitting.
• Nitrogen: Nitrogen is passed through the line during brazing. This prevents oxide (scale) from forming inside the tube and keeps this residue from being carried to the filter drier and the expansion valve.
• Heating: The joint area is heated evenly. The rod is melted not directly by the flame but by the heat of the warmed tube; heating is stopped once the rod flows around the tube.
• Brass parts: In copper-to-brass joints such as valve bodies, flare nuts or filter drier connections, flux is applied to the surface.
• Where not to use: Phosphor rod is not used on steel, cast iron, stainless steel, nickel alloys or the copper-plated steel connections found on some compressor fittings. For these connections, silver brazing rod is used together with flux. It is also not suitable for joints that will operate in sulfurous environments.
• Safety: Do not inhale brazing fumes, work in a ventilated area and wear safety goggles.