Insights
December 11, 2025 · 5 min read · Process
You have an 858 Percussion Welder, a 726 Bench Fixture, two pieces of metal that need to become one piece of metal, and approximately zero idea where to start. This guide is for you.
Percussion welding isn't complicated, but it does have a sequence. Skip steps and you'll spend an hour troubleshooting what should've taken ten minutes. Follow the sequence and you'll be making welds before your coffee gets cold.
This guide walks through setting up a weld from scratch—loading parts, establishing energy settings, dialing in the actuator timing, and validating your first good welds. We'll use a common scenario: welding a stranded copper wire to a solid steel pin.
Before You Start: If you're welding a material combination that's already in your weld schedule library, just recall those settings and skip to Step 6. This guide is for developing a new schedule from scratch.
Chapter 01 / 10
What You'll Need
Equipment
- 858 Percussion Welder
- 726 Bench Fixture
- Appropriate wireholders
- Ground clip
- Safety glasses
Materials & Tools
- Sample workpieces (plenty of them)
- Cleaning solvent & lint-free wipes
- Feeler gauges
- Pull tester (for validation)
- Notepad or schedule worksheet
01
Chapter 02 / 10
Load the Workpieces
Get the parts in position before touching any electrical settings
Place the solid pin (the more rigid workpiece) in the stationary wireholder. Place the stranded wire (the more flexible workpiece) in the moveable wireholder.
Attach a ground clip to the tail end of the stranded wire. This completes the circuit path for the weld energy.
💡 WHY THIS ORDER?
The moveable wireholder accelerates toward the stationary one. Putting the more flexible piece in the moving holder gives you better control over the collision dynamics and reduces the chance of buckling or misalignment at impact.
02
Want to see it on your parts?
Send samples and we'll run test welds before you commit.
Chapter 03 / 10
Set the Gap
The air space between workpieces before the weld fires
Use the fixture's adjustment controls to bring the two weld points to a pre-defined gap. The general rule:
Gap = ½ the diameter of the smaller workpiece or 0.020", whichever is less
For most micro-welding applications, you'll be in the 0.010" to 0.040" range. Use a feeler gauge to verify—don't eyeball it.
The gap affects arc duration and impact timing. Too small = weak arc development. Too large = excessive burn time and poor coordination between heating and forging.
03
Chapter 04 / 10
Set the Slippage
How much the workpiece can move in the holder on impact
Adjust the spring tension on the moveable wireholder. You want the workpiece held firmly enough that it doesn't move during normal handling, but loose enough that it can slip slightly upon impact.
Test it with your fingers: moderate pressure should cause the workpiece to slide in the holder. If it's locked solid or flopping around freely, adjust accordingly.
💡 WHY SLIPPAGE MATTERS
When the parts collide, controlled slippage reduces peak impact force and helps expel oxides from the weld interface. Zero slippage can cause molten metal to splash. Too much slippage means inconsistent positioning.
04
Chapter 05 / 10
Establish the Energy Setting
Find the right amount of heat to melt the workpieces
Set the Actuator to zero first. We're going to find the energy setting before we add motion. This isolates variables.
Start with these baseline settings on the 858:
| Parameter | Starting Value | Notes |
|---|---|---|
| Mode | Regular | Switch to Heavy Duty only if needed |
| Capacitors | 1 | Start low, increase if insufficient melt |
| Voltage | 75V | Middle of the range |
| Pulse Width | Long | More forgiving for initial testing |
| Polarity | Positive | Copper usually runs on + when joining to steel |
With actuator at zero, fire the welder using the start lever. You're looking for a small ball of molten metal forming on the end of each workpiece—proof that you've reached the melting point.
If nothing melts: increase capacitor setting (1 → 2 → 3) and try again. If it melts but looks uneven between the two pieces, try switching polarity.
05
Want to see it on your parts?
Send samples and we'll run test welds before you commit.
Chapter 06 / 10
Dial In the Actuator
Add motion to forge the weld
Now that you know your energy settings melt the materials, it's time to make them collide at the right moment.
Set the Delay to 2.0 milliseconds as a starting point. This controls how long after the actuator fires before the weld energy discharges.
Set the Actuator voltage to 50V and fire a weld. Check the result:
✗ No weld / parts didn't fuse Actuator too slow—arc extinguished before contact. Increase actuator voltage by 5V. ✗ Short circuit / no arc visible Actuator too fast—parts touched before arc formed. Decrease actuator voltage by 5V. ✓ Visible arc + parts fused You're in the zone. Now fine-tune with small adjustments.
Once you have a weld forming, adjust the Delay to optimize. Higher delay = shorter arc burn time before impact. Lower delay = longer arc burn time. Find the sweet spot where the weld looks clean with minimal splatter.
06
Chapter 07 / 10
Fine-Tune and Validate
Optimize for strength, appearance, and consistency
You have a working weld. Now make it a good weld. Adjust one parameter at a time and observe the effect:
| To Achieve... | Try Adjusting... |
|---|---|
| More penetration / larger nugget | Increase voltage or capacitance |
| Less splatter / cleaner appearance | Reduce actuator speed, adjust delay timing |
| More balanced melt between parts | Try opposite polarity |
| Shorter heat-affected zone | Short pulse width, lower energy, faster actuation |
| Stronger weld joint | Optimize slippage, verify cleanliness, pull test samples |
Run a batch of 10-20 sample welds. Pull test them. Look for consistency in both appearance and strength. If you're seeing variation, something in your setup isn't locked down—revisit gap, slippage, and part cleanliness.
Pro Tip: Use the Weld Monitor
The Percussion Weld Monitor gives you waveform data on each weld. During schedule development, this is gold—you can see exactly how energy is being delivered and correlate it with weld quality. Takes the guesswork out of fine-tuning.
07
Chapter 08 / 10
Document and Save
Future you will thank present you
You've developed a working weld schedule. Now write it down before you forget any of it.
Weld Schedule Documentation Checklist:
☐ Material 1: type, diameter, supplier ☐ Material 2: type, diameter, supplier ☐ Gap setting (with tolerance) ☐ Slippage setting (grams) ☐ Capacitor setting (1, 2, 3, 2HD, 3HD) ☐ Polarity (+ or −) ☐ Weld voltage ☐ Pulse width (Long or Short) ☐ Actuator voltage ☐ Delay time (ms) ☐ Pull test results (min/max/avg) ☐ Date developed, engineer name
Save this schedule with a clear naming convention. When an operator needs to run this part six months from now, they should be able to recall everything without rediscovering it from scratch.
Want to see it on your parts?
Send samples and we'll run test welds before you commit.
Chapter 09 / 10
Quick Reference: The Setup Sequence
1. Load workpieces — rigid piece stationary, flexible piece moving 2. Set gap — ½ smaller diameter or 0.020", whichever is less 3. Set slippage — firm hold with moderate-pressure slip 4. Find energy — actuator at zero, adjust until both pieces melt 5. Dial actuator — start at 50V, adjust until arc + fusion 6. Fine-tune — optimize appearance, test strength 7. Document — save everything for future recall
Chapter 10 / 10
The Pattern to Remember
Mechanical setup first (loading, gap, slippage), then energy (capacitors, voltage, polarity, pulse), then motion (actuator, delay). Isolate variables. Change one thing at a time. Document everything.
Follow this sequence and you'll develop reliable weld schedules faster—with fewer mystery failures and less wasted material.
Need Help With a Tricky Material Combination?
Some joints are straightforward. Some require expertise. If you're stuck on schedule development or want to validate your approach before production, we can help.
Bring your materials. We'll help you find the schedule.
Related Reading
Part of: Process & Technique
More on process & technique
How Percussion Welding Works →FAQ
What is percussion welding?
A heat-plus-impact process for joining metals.
An electric arc supplies the heat, then a rapid mechanical movement forces the two materials together, forming a full metallic bond with no filler.
Do I need filler metal, solder or flux?
No. There's no filler, solder or flux, and no electrodes to wear out.
That means cleaner joints, less waste, and no consumables to buy.
How do I know if my materials can be welded?
Start with the Parameter Finder or the weld schedules table.
If your pair isn't listed, tell us your weld challenge. We'll reply with a straight answer about whether percussion welding is a fit, and how.
Still have a question? Tell us your weld challenge and an engineer will reply.
Start here
Share what you're joining and what's going wrong. We'll tell you straight whether percussion welding is a fit.
Prefer to talk? Book a demo or call 303-536-7838