Nickel Alloy BNi-6
UNS N99700 · ISO B-Ni6
BNi-6 is a chromium-free nickel-phosphorus brazing filler metal (UNS N99700) in the AWS A5.8 family, self-fluxing on nickel and stainless surfaces at a relatively low brazing temperature.
Reference datasheet — BNi-6 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
BNi-6 tempers and conditions
BNi-6 is supplied in one standard condition, AS-BRAZED.
Supply forms, finishes and certifications
Ways BNi-6 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
PREFORM | Sintered or binder-bonded rings, washers, shims and tape | Supply form |
PASTE | BNi-6 powder pre-mixed with organic binder for dispensing/screening | Printing process |
POWDERDefault | Gas-atomised BNi-6 braze powder | Printing process |
What is BNi-6?
BNi-6 is a chromium-free nickel-phosphorus brazing filler metal (UNS N99700) in the AWS A5.8 family, self-fluxing on nickel and stainless surfaces at a relatively low brazing temperature. It is chosen for low-temperature furnace brazing of instrument and electronic assemblies where furnace capability or parent-metal heat input is limited; deposit density is 7.7 g/cm3 and maximum service temperature is 425 C. The solidified Ni3P eutectic is brittle, the joint cannot be weld repaired, and the chromium-free fillet limits corrosion resistance. BNi-7 adds chromium for better corrosion performance at a similar phosphorus base. BNi-6 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 97% of nickel alloy grades. It melts at 875°C (1,607 °F). The elastic modulus is 130 GPa (18.9 Msi).
What is BNi-6 used for?
- Low-temperature nickel brazing
- Corrosion-resistant electronic joints
- Instrument and sensor assemblies
- Thin-wall stainless steel components
- Vacuum-brazed fittings for moderate temperature
- Heat exchanger plate joints
Limitations
- Low stiffness — 130 GPa (18.9 Msi), worse than 99% of nickel alloy grades
- Hard to polish — 50/100, worse than 98% of nickel alloy grades
- Needs corrosion protection — 35/100, worse than 96% of nickel alloy grades
- Difficult to weld — 10/100, worse than 94% of nickel alloy grades
- Difficult to machine — 10/100, worse than 93% of nickel alloy grades
BNi-6 properties
Typical room-temperature values; bars are the position among nickel alloy grades.
Physical3
BNi-6 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 97% of nickel alloy grades. It melts at 875°C (1,607 °F).
Mechanical4
The elastic modulus is 130 GPa (18.9 Msi).
Thermal5
BNi-6 is rated for continuous service to 425°C (797 °F). It conducts heat at 10 W/m·K (5.78 BTU/hr·ft·°F), worse than 88% of nickel alloy grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical2
BNi-6 has an electrical resistivity of 1×10⁻⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is fair (35/100), worse than 96% of nickel alloy grades.
Sustainability4
Producing a kilogram of BNi-6 takes about 155 MJ of energy and emits 13 kg of CO₂ — less than 58% of nickel alloy grades. Typical recycled content is 10%.
Manufacturability4
BNi-6's machinability is not recommended (10/100, worse than 93% of nickel alloy grades); weldability not recommended (10/100).
Common Calculations2
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. BNi-6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BNi-6
Is BNi-6 easy to machine?
Solidified BNi-6 is a hard, brittle Ni₃P eutectic — remove excess fillet by grinding or blending, not by turning or milling.
Can BNi-6 be welded?
Do not fusion weld over or through a BNi-6 joint; phosphorus pickup causes hot cracking in the weld metal.
Can BNi-6 be formed, bent or molded?
Supplied only as powder, paste or bonded preform — the alloy cannot be drawn to wire or rolled to ductile foil.
BNi-6 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Peutectic-forming element; gives single melting point ~875 °C | 10 – 12 | 11 |
| C | ≤ 0.1 | 0.03 |
| Si | ≤ 0.1 | |
| Femaximum (residual) | ≤ 0.2 | |
| S | ≤ 0.02 | |
| Other (total)sum of residuals per AWS A5.8 | ≤ 0.5 | |
| Nibalance, nominally ~89 % | balance |
What surface finishes work on BNi-6?
Self-fluxing, so no flux residue in vacuum/hydrogen brazing; passivate stainless assemblies after brazing but avoid strong oxidising acids that attack the Cr-free fillet.
Surface treatments FabDigit runs on nickel alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy BNi-6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N99700
- ISO
- B-Ni6
How much does BNi-6 cost?
BNi-6 is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BNi-6 — frequently asked
What is BNi-6 used for?
BNi-6 is typically used for low-temperature nickel brazing, corrosion-resistant electronic joints, instrument and sensor assemblies, thin-wall stainless steel components, vacuum-brazed fittings for moderate temperature and heat exchanger plate joints. In short: self-fluxing Ni-P braze; low brazing temperature; 425 C service ceiling.
Is BNi-6 easy to machine?
Not especially — machinability is rated not recommended (10/100, worse than 93% of nickel alloy grades). Solidified BNi-6 is a hard, brittle Ni₃P eutectic — remove excess fillet by grinding or blending, not by turning or milling.
Can BNi-6 be welded?
Not readily — weldability is rated not recommended (10/100). Do not fusion weld over or through a BNi-6 joint; phosphorus pickup causes hot cracking in the weld metal.
What surface finishes work on BNi-6?
Self-fluxing, so no flux residue in vacuum/hydrogen brazing; passivate stainless assemblies after brazing but avoid strong oxidising acids that attack the Cr-free fillet.
Can BNi-6 be formed, bent or molded?
Supplied only as powder, paste or bonded preform — the alloy cannot be drawn to wire or rolled to ductile foil.
What is the maximum service temperature of BNi-6?
BNi-6 is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BNi-6 cost?
BNi-6 is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- AWS A5.8M/A5.8 Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (nickel braze filler metals) — ASM International (1993)
- AWS Brazing Handbook, 5th ed. — American Welding Society (2007)
- Nickel braze filler metal powder/paste datasheets (BNi-6, Ni-11P) — Braze-alloy producers (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.