Description
Harris Stay-Silv® 15 Silver-Phosphorus Brazing Alloy – 28 Stick Tube
Harris Stay-Silv® 15 brazing alloy, part number 15620F1, is a 15% silver phosphorus-copper filler metal widely used for HVAC, air-conditioning, refrigeration, plumbing, and copper-tube brazing. Stay-Silv® 15 has long been recognized as an industry-standard alloy for joining copper because it combines dependable flow characteristics, strong capillary action, and a relatively wide melting range.
The wider melting range helps Stay-Silv® 15 bridge less-than-perfect joint fit-up and allows the operator to build or cap a finished joint when needed. When heated above its liquidus temperature, the alloy will also flow into properly fitted capillary joints. On copper-to-copper connections, the phosphorus content makes the alloy self-fluxing, eliminating the need for a separate brazing flux.
Product Highlights
- Premium 15% silver phosphorus-copper brazing alloy
- Industry-standard filler metal for HVAC and refrigeration work
- Excellent choice for copper-to-copper brazing
- Self-fluxing on copper — no separate flux required for copper-to-copper joints
- Wide melting range helps accommodate wider joint clearances
- Flows into tight capillary joints when heated above liquidus temperature
- Recommended joint clearance of 0.003–0.006 in.
- Suitable for copper-to-brass and brass applications when used with appropriate brazing flux
- Corrosion resistance generally similar to copper base metal
- Conforms to AWS A5.8 BCuP-5
- Harris manufacturer part number 15620F1
Technical Specifications
Base-Metal & Flux Guidance
Copper-to-Copper
- No separate flux is required
- Phosphorus in the alloy provides self-fluxing action on copper
- Excellent for copper tube and fitting connections
- Commonly used throughout HVAC and refrigeration systems
Brass & Copper-to-Brass
- Use an appropriate brazing flux
- Harris Stay-Silv® White Flux is suitable for many applications
- Harris ECO SMART® boric-acid-free flux may also be used where appropriate
- Clean base metals and proper joint preparation remain important
Common Applications
HVAC & Refrigeration
- Air-conditioning refrigerant lines
- Refrigeration piping systems
- Copper line-set connections
- Compressor and equipment connections
- HVAC installation and repair
- Service and maintenance work
Plumbing & Mechanical
- Copper tube brazing
- Copper fittings and couplings
- Copper-to-brass connections with flux
- Mechanical piping assemblies
- General copper fabrication
- Maintenance and repair applications
Why Stay-Silv® 15 Is Popular for HVAC
Stay-Silv® 15 has been widely used in the air-conditioning and refrigeration industry because its brazing characteristics work well with copper tubing systems that experience temperature changes, vibration, and repeated service cycles.
Its relatively wide melting range also gives the technician more flexibility when joint fit-up is not perfectly uniform. The alloy can help bridge wider clearances while still providing good capillary flow in properly heated, close-fitting joints.
For copper-to-copper joints, the ability to braze without adding a separate flux also simplifies field installation and reduces post-braze flux cleanup.
Joint Fit-Up & Brazing Performance
Harris recommends a joint clearance of approximately 0.003–0.006 in. for Stay-Silv® 15. Proper clearance helps promote capillary action and allows the molten filler metal to distribute through the joint.
Because Stay-Silv® 15 has a wider melting range than more fluid phosphorus-copper alloys, it can also be useful where a slightly wider clearance must be filled or where the operator needs to build a fillet around the completed joint.
Composition & Specification Compliance
Product Resources
Review current Harris manufacturer information, brazing procedures, and safety documentation before final filler-metal selection or use.
Need Help Selecting a Brazing Alloy?
Our GetPipe.com team can help compare Stay-Silv® 15 with other Harris phosphorus-copper and silver brazing alloys, confirm base-metal compatibility, review joint-clearance requirements, and help with brazing fluxes, torches, regulators, and related HVAC supplies.
Frequently Asked Questions
What is Harris Stay-Silv® 15 used for?
Stay-Silv® 15 is commonly used for brazing copper tubing and fittings, especially in HVAC, refrigeration, air-conditioning, plumbing, and mechanical piping systems.
How much silver is in Stay-Silv® 15?
Stay-Silv® 15 contains approximately 15% silver. Harris lists a typical silver-composition range of 14.5–15.5%.
Does Stay-Silv® 15 require flux on copper?
No separate flux is normally required when brazing copper to copper. The phosphorus content in Stay-Silv® 15 provides self-fluxing action on copper.
Do I need flux when brazing copper to brass?
Yes. Harris recommends using an appropriate brazing flux when joining brass or copper to brass with Stay-Silv® 15. Stay-Silv® White Flux is suitable for many applications.
Can Stay-Silv® 15 be used on steel?
Harris does not recommend Stay-Silv® 15 for steel or other ferrous metals because phosphorus-copper alloys may not provide adequate joint ductility on those base materials.
What joint clearance is recommended for Stay-Silv® 15?
Harris recommends approximately 0.003–0.006 in. (0.076–0.152 mm) of joint clearance.
What is the melting temperature of Stay-Silv® 15?
Harris lists a solidus temperature of approximately 1190°F (643°C) and a liquidus temperature of approximately 1475°F (802°C), with a typical brazing range of about 1300°F–1500°F.
What AWS classification is Stay-Silv® 15?
Stay-Silv® 15 conforms to ANSI/AWS A5.8 Class BCuP-5 and ASME SFA 5.8 Class BCuP-5.
How is Harris part number 15620F1 packaged?
Harris lists part number 15620F1 as .050 x 1/8 in. brazing strip, 28 in. long, packaged as 28 sticks per tube.
Why is Stay-Silv® 15 commonly used in refrigeration systems?
Its combination of copper compatibility, self-fluxing performance, wide melting range, and ability to accommodate normal system vibration and thermal expansion has made Stay-Silv® 15 a common choice for air-conditioning and refrigeration copper connections.
Can Stay-Silv® 15 be used on copper-nickel alloys?
Harris states that Stay-Silv® 15 is generally suitable for low-nickel copper/nickel base metals containing up to approximately 10% nickel. Application suitability should still be verified before use.
Can Stay-Silv® 15 be used where sulfur is present?
Harris advises against using phosphorus-containing brazing alloys, including Stay-Silv® 15, where the finished joint will be exposed to sulfur or sulfur compounds in service.
Important Brazing & Safety Notes
- Use proper joint preparation, cleaning, fit-up, and heating practices before applying filler metal.
- No separate flux is normally required for copper-to-copper brazing.
- Use an appropriate brazing flux when joining brass or copper to brass.
- Stay-Silv® 15 is not recommended for steel or other ferrous base metals.
- Do not use phosphorus-containing alloys where joints will be exposed to sulfur or sulfur compounds in service.
- Verify base-metal compatibility and brazing procedure requirements before use.
- Do not overheat the base metal or filler alloy; use uniform heating to promote proper capillary flow.
- Brazing fumes and gases can be hazardous. Use adequate ventilation and follow applicable hot-work procedures.
- Wear appropriate eye, hand, and body protection during brazing operations.
- Review current Harris technical information, safety documentation, and workplace requirements before use.
