Harris Safety-Silv 56 (part number 5631) is a premium-grade, cadmium-free silver brazing filler metal containing 56% silver, classified AWS A5.8 BAg-7. Available in 1/16 in (1.6 mm) diameter wire in a 1 troy-ounce cup — ideal for precision work, repair shops, and contractors who need a small quantity of the highest-performing silver braze available. Safety-Silv 56 delivers the lowest liquidus temperature (1,205 °F / 652 °C) of all the major Harris high-silver alloys, the narrowest melting range (60 °F / 33 °C), and the highest fluidity — making it the preferred choice for tight capillary joints, thin-section assemblies, and any application where minimal heat input is critical. NSF Standard 51 certified for food service equipment. Complies with EU REACH and RoHS directives.
| Property | Value |
|---|---|
| AWS Classification | AWS A5.8 BAg-7 |
| ASME Specification | ASME SFA-5.8 BAg-7 |
| Other Standards | QQ-B-654A Class BAg-7; AMS 4763; NSF ANSI 51 |
| Silver (Ag) | 56 % |
| Copper (Cu) | 22 % |
| Zinc (Zn) | 17 % |
| Tin (Sn) | 5 % |
| Solidus | 1,145 °F (618 °C) |
| Liquidus | 1,205 °F (652 °C) |
| Melting Range | 60 °F (33 °C) — very narrow |
| Wire Diameter | 1/16 in (1.6 mm) |
| Package | 1 troy oz cup |
| Part Number | 5631 |
| Cadmium Free | Yes |
| NSF Certification | NSF Standard 51 — food service equipment |
| Flux Required | Yes — Harris Stay-Silv White Flux |
| Recommended Joint Clearance | 0.001 – 0.003 in (0.025 – 0.075 mm) |
Safety-Silv 56 (BAg-7) is the alloy of choice wherever the combination of lowest brazing temperature, maximum fluidity, and tightest joint clearance is required.
- Stainless steel food service equipment — NSF 51 certified; ideal for brazed joints on food-contact surfaces, commercial kitchen equipment, dairy processing, and pharmaceutical hardware
- Thin-section stainless and steel fabrications — lowest liquidus (1,205 °F) minimizes heat distortion on thin gauge materials
- Carbide tooling and inserts — excellent capillary flow into tight carbide-to-steel braze joints; high strength and ductility resist cutting shock
- Electrical and electromechanical assemblies — relay contacts, terminal lugs, and switchgear components requiring high conductivity and heat resistance
- HVACR service (dissimilar metals) — when copper-to-steel or copper-to-stainless connections must be brazed at minimum heat input
- Medical device fabrication — the 56% silver content, cadmium-free composition, and NSF certification make it acceptable for many medical and laboratory instrument joints
Safety-Silv 56 has a very narrow 60 °F melting range and a high fluidity rating — it flows quickly once the liquidus is reached. This requires careful torch control: heat the base metal uniformly and apply alloy as soon as the flux turns water-clear. Over-heating can cause the alloy to run through the joint before proper capillary draw occurs, wasting alloy and leaving under-filled joints. Work with a soft, neutral-to-slightly-reducing flame and keep torch movement consistent.
Unlike BCuP alloys, Safety-Silv 56 (BAg-7) does not contain phosphorus and is not self-fluxing. Always use Harris Stay-Silv White Brazing Flux on all joint surfaces before heating. Apply flux generously to cover all metal surfaces within 1 in of the joint. Quench and wire-brush to remove all flux residue after brazing — flux residue left in place will cause corrosion over time.
| Property | Safety-Silv 56 (BAg-7) | Safety-Silv 45 (BAg-5) |
|---|---|---|
| Silver content | 56% | 45% |
| Liquidus | 1,205 °F (652 °C) | 1,370 °F (743 °C) |
| Melting range | 60 °F — narrow | 145 °F — wider |
| Fluidity | Very high | High |
| Joint clearance | Tight: 0.001–0.003 in | Wider: 0.002–0.005 in |
| NSF 51 certified | Yes | No (bare wire 45) |
| Cost | Higher (more silver) | Moderate |
- What AWS classification is Safety-Silv 56?
- AWS A5.8 BAg-7 / ASME SFA-5.8. Contains 56% Ag, 22% Cu, 17% Zn, 5% Sn. Also AMS 4763 and NSF ANSI 51.
- What is the melting temperature of Safety-Silv 56?
- Solidus 1,145 °F (618 °C); liquidus 1,205 °F (652 °C). Narrowest melting range (60 °F) in the Safety-Silv family — flows rapidly once liquidus is reached.
- Is Safety-Silv 56 approved for food service?
- Yes — NSF ANSI Standard 51 certified, cadmium-free, and lead-free.
- Does Safety-Silv 56 need flux?
- Yes — use Harris Stay-Silv White Brazing Flux. Not self-fluxing. Remove all flux residue after brazing.
Browse the full brazing alloy collection. Compare to the Harris Safety-Silv 56 coil box (5615) for higher-volume use, and the Harris Safety-Silv 45 (BAg-5) when a wider melting range is preferred. Specification reference: Harris Products Group and AWS A5.8.