Harris L-CuP6 Square Phosphor Copper Brazing Rod 2x2x500 mm

The Harris L-CuP6 square phosphor copper brazing rod comes in rods with a 2x2 mm square cross-section 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. In refrigeration and air conditioning installations it is used for copper-to-copper pipe brazing without flux.

L-CuP6 Rod Requiring No Flux in 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 pipe to copper pipe 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 uses.

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: Square (square cross-section)
• Size: 2 x 2 mm cross-section, 500 mm length
• Cross-sectional area: 4 mm²
• Melting range: 710 – 890 °C
• Working temperature: 760 °C
• Density: 8.1 g/cm³
• Flux: Not required for copper-copper · required for copper-brass and copper-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. A square rod carries approximately 27% more filler material for the same length; in the same 1 kg, however, a round rod yields more rods. Because it delivers more material per rod, the square rod allows work on large-diameter pipes and wide joints with fewer rod changes.

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 and accurate fits it spreads easily into the joint by capillary action. L-CuP6 has a wider melting range and flows more sluggishly. This property makes work easier in filling fits that are not fully seated and when brazing in vertical or overhead positions.

Application Notes

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