BCu93P Silver-Free Copper-Phosphorus Brazing Rod | For Copper Tube Brazing
HL201 / BCuP-2 Copper-Phosphorus Brazing Alloy | Self-Fluxing | For Air Conditioning, Refrigeration & Motor Copper ComponentsProduct Overview
BCu93P (HL201 / BCuP-2) is a silver-free copper-phosphorus brazing rod designed for copper-to-copper and copper-to-brass joints. With excellent self-fluxing properties and melt fluidity, it is widely used for torch brazing of copper tubes in air conditioning and refrigeration systems, motor copper components, and general copper pipe connections.The phosphorus content acts as a self-fluxing agent when brazing pure copper, eliminating the need for additional flux — simplifying operation and reducing consumable costs.
Key Advantages
Self-Fluxing for Pure Copper Brazing
No additional flux required when brazing pure copper. The phosphorus element serves as a self-fluxing agent during the brazing process, reducing steps and saving costs. Note:Flux is still required when brazing brass or copper-to-iron joints.
Excellent Fluidity & Capillary Gap-Filling
The filler metal flows well when molten and penetrates extremely tight joints. Recommended joint clearance: 0.025–0.075mm (0.001"–0.003") for dense, reliable brazed seams.
Silver-Free, Cost-Effective
Compared to silver-bearing copper-phosphorus filler metals, the 0% silver formulation significantly reduces material costs while maintaining reliable performance for copper-to-copper joints — ideal for high-volume production.
Stable Storage, Low Oxidation Risk
Stable processing performance with low surface oxidation risk under normal storage conditions.
Technical Specifications
| Item | Parameter |
|---|---|
| AWS Standard | BCuP-2 |
| ISO Standard | CuP 181 |
| GB Grade | BCu93P |
| Former Machinery Ministry Grade | HL201 |
| Chemical Composition | P: 7.0–7.5%, Cu: Balance |
| Silver Content | 0% |
| Solidus | 710°C (1310°F) |
| Liquidus | 793°C (1460°F) |
| Recommended Brazing Temp. | 730–845°C |
| Joint Clearance | 0.025–0.075mm |
| Density | Approx. 7.83 g/cm³ |
| Tensile Strength | 705–790 MPa |
| Electrical Conductivity | 23–25 %IACS |
| Base Metals | Copper (self-fluxing), Brass (flux required) |
Complies with AWS A5.8, ASME SFA5.8, and ISO 17672 CuP 181 specifications.
Usage Recommendations
Surface Preparation: Thoroughly remove grease, oxides, and other contaminants from the surfaces to be brazed. Maintain joint clearance within 0.025–0.075mm. Excessive clearance weakens capillary action and compromises seam density.
Heating Guidelines: When torch brazing, heat as quickly and evenly as possible. Slow heating can cause segregation of the copper-phosphorus filler metal (separation into high- and low-melting-point constituents), degrading joint quality. A neutral or slightly reducing flame is recommended.
Brass Brazing Note: When brazing brass, use a silver brazing flux (such as Stay-Silv white flux or equivalent) for better wetting and spreading.
Post-Braze Cleaning: The brazed joint surface appears light gray. To restore the copper color, immerse in a 10% sulfuric acid solution.
Applications
Air Conditioning & Refrigeration: Copper tube connections, evaporators, condensers, heat exchangers, compressor lines
Refrigerators & Freezers: Copper tube joint brazing in refrigeration systems
Motors & Electrical:Motor copper components, transformer copper bars, electrical contact connections
General Copper Piping:Copper water pipes, water heaters, copper radiators
Important Limitations
Not recommended for joints under impact or vibration loads.The high phosphorus content limits joint ductility, creating a risk of cracking under dynamic loading. For vibration-prone applications, consider silver-bearing copper-phosphorus filler metals (e.g., BCuP-5).
Not for ferrous or nickel-based alloys. Phosphorus forms brittle phosphides with iron or nickel, causing interfacial embrittlement and a sharp drop in joint strength.
Avoid use in sulfur-containing media. Corrosion resistance decreases significantly when joints are exposed to sulfur or sulfide environments.
FAQ
Q: Is flux required when brazing brass?
A: Yes. The self-fluxing property of BCu93P applies only to pure copper brazing. Brass, copper-to-brass, and copper-to-iron joints all require flux.
Q: What is the recommended brazing temperature?
A: The melting range is 710–793°C, with a recommended working temperature of approximately 730–845°C. In practice, heat the base metal to brazing temperature first, then feed the filler rod to the joint edge — the base metal heat melts the filler.
Q: What joint clearance should be used?
A: Optimal capillary clearance is 0.025–0.075mm (0.001"–0.003"). Excessive clearance weakens capillary action; insufficient clearance may prevent filler penetration.
Q: Can it be used for copper-to-aluminum joints?
A: No. BCu93P is only suitable for brazing copper and copper alloys (brass). It is not suitable for aluminum, steel, or nickel-based alloys.