Insights
May 27, 2026 · 2 min read · Materials
Lab data · 4 tested schedules
- Wire diameter
- .025"–.040"
- Actuator velocity
- 62–78 V
- Weld voltage
- 60–100 V
- Delay time
- 1.00–1.50 ms
Starting points from our lab experiments, not guaranteed settings. Validate on your own parts.
Chapter 01 / 05
Niobium to Tungsten
Tungsten and niobium are both refractory metals with very high melting points, and both oxidize readily at elevated temperatures.
Conventional welding of this pair is often done with electron beam (EB) welding in a vacuum.
Percussion welding joins niobium to tungsten in open atmosphere, on benchtop equipment, with a cycle time measured in milliseconds.
The Energy Challenge
Bringing two refractory metal surfaces to their melting points simultaneously requires a high energy concentration, even for small-diameter wire.
Verified Weld Parameters: Niobium to Tungsten
| Wire Dia. | Velocity (V) | Delay time (ms) | Cap | Weld voltage (V) | Pulse |
|---|---|---|---|---|---|
| 0.026" | 70V | 1.50 | Cap2 | 100V | Short |
| 0.040" | 70V | 1.50 | Cap2 | 100V | Short |
Identical Parameters Across Diameters
The Nb-W lab schedules use the same velocity, delay time, capacitance, voltage and pulse settings for both the 0.026" and 0.040" wire diameters.
Related Resources
View the complete Nb-W parameter database at Weld Schedules.
Chapter 02 / 05
How to read and use these settings
Each lab schedule lists the wire diameter and the 858 settings used to make a good weld in our lab:
- Actuator velocity (V): the voltage applied to the actuator, which sets how fast it drives the moving wire holder. The 858 actuator speed is 0–33 inches per second across 0–150 V.
- Delay time (ms): the timing delay setting on the 858.
- Cap: the capacitor bank setting: 1, 2 and 3 are the regular banks and 1HD, 2HD and 3HD are the heavy-duty banks.
- Voltage (V): the weld-energy (bank) voltage.
- Pulse: the pulse width, long or short.
Treat them as starting points. Actual alloys and the masses of the materials vary, so your final schedule comes from small adjustments. We strongly recommend varying a single parameter at a time and testing the result: that makes patterns easier to see and gets the best strength and appearance faster. Always run test welds and validate joint strength on your own parts before production.
Want to see it on your parts?
Send samples and we'll run test welds before you commit.
Chapter 03 / 05
Surface preparation
Clean and degrease both materials and remove oxides, oils and contamination from the weld area. Material notes from our process team:
- Niobium: Clean thoroughly. Avoid contamination.
- Tungsten: Clean the surface carefully. Remove any oxidation.
Chapter 05 / 05
Test your own samples
Send us your niobium and tungsten parts. Free applications tests of your materials are available, and we can run live, in-person tests at our lab in Denver. Tell us your weld challenge or call 303-536-7838.
FAQ
What are starting settings for niobium to tungsten welding?
Our lab has 4 schedules for Niobium and Tungsten. For example, .025" wire: 62 V actuator velocity, 60 V weld voltage, 1.50 ms delay, capacitance setting 3, short pulse.
These are starting points, not guarantees. Change one setting at a time and test.
Which wire diameters have lab schedules for niobium to tungsten?
.025", .026", .030", .040". If your wire size is different, send samples and we will develop and verify a schedule.
Does niobium to tungsten percussion welding need filler, solder or flux?
No. Percussion welding joins the two base metals directly, with no filler material, solder or flux and a minimal heat-affected zone.
Can you test my niobium and tungsten samples?
Yes. Free applications tests of your materials are available, and we can run live, in-person tests at our lab in Denver. Call 303-536-7838 or send your weld challenge.
Still have a question? Tell us your weld challenge and an engineer will reply.
Start here
Free applications tests of your materials are available. Tell us what you are joining.
Prefer to talk? Book a demo or call 303-536-7838