Equipment
0-150 V
bank voltage range
0.5-5.0 ms
timing delay, adjustable
0-30 J
actuator energy into 0.6 ohms
3 + 3
capacitor banks, Regular and Heavy Duty
The 858 is a precision capacitor discharge micro welder built for the joints that resistance, arc, and laser welding can't deliver cleanly — thermocouple wire, dissimilar metals, and fine-wire assemblies where heat damage, contamination, and inconsistent results aren't options.
Unlike spot welding (which presses two materials together with current), arc welding (which uses sustained electrical arcs), or flash welding (which fuses entire surfaces with high pressure), percussion welding releases a millisecond burst of energy from a capacitor bank to forge two materials together with virtually no heat-affected zone. The result: cleaner welds, no filler material, and the ability to join metals other processes simply can't.
The 858 is the industry standard for thermocouple welder applications, fine-wire joining, and dissimilar metals welding across aerospace, defense, electronics, battery, and industrial sensor manufacturing.
Chapter 01 / 03
Our Micro Wire Welding Machine Process
The Percussion Welder Model 858 is a top micro arc welding machine. It allows two wires of similar or dissimilar metals to be welded together quickly, efficiently, and with precision and control.
The Model 858 is the control system for the bench unit, and it offers precision adjustment for different metals, diameters of materials, and the specific current required for the process. This control over the micro welders equipment is user-friendly, with dial control over the actuator, delay, and weld energy voltage control.
The user can also adjust the mode, pulse, polarity, and capacitance for each weld using clearly marked switches on the panel. The system is ready to use upon arrival, and with intuitive operation, our micro spot welding machine is easy to integrate into any process.
Our mirco welding equipment is ideal for manual operation, but it is easily adaptive and integrated into automated production lines and processes. The Model 858 micro welding machine system comes with the Model 726 Bench Fixture and the optional Percussion Weld Monitor that tests welds for customizable good/no good quality control.
If you have any questions about our micro welding machines, or if you are struggling to find a micro welding solution, call us at 303-536-7838 or reach out to us online.
Advanced Control Features
The 858 Percussion Welder offers a suite of advanced control features that make it an indispensable tool for precision micro-welding. The front panel is equipped with user-friendly controls that allow operators to fine-tune every aspect of the welding process. From adjusting the actuator and delay settings to controlling the weld energy voltage, the 858 provides unparalleled precision and flexibility.
Operators can select from various mode settings, including regular and heavy-duty, to match the requirements of their specific application. The ability to control pulse width, polarity, and capacitance ensures that each weld is optimized for strength and durability. These features make the 858 Percussion Welder a versatile solution for a wide range of micro-welding tasks.
| SPECIFICATIONS | |
| AC Input: | 110-120 VAC 60 Hz 20 amp peak; 200~220 VAC 50~60 Hz 10 amp peak |
| Circuit Protection: | 10 amp or 20 amp fuse (see above) |
| Capacitance: | Regular: Bank 1 330 µF Bank 2 1,830 µF Bank 3 8,430 µF Heavy Duty: Bank 1 10,230µF Bank 2 11,730µF Bank 3 18,330µF |
| Bank voltage range: | 0-150V |
| Repetition rate: | |
| Timing Delay: | 0.5 to 5.0 milliseconds |
| Triggering: | Closed contact 15v |
| Polarity: | Positive or Negative: User Selectable |
| Actuator Energy: | 0 to 30 Joules into 0.6 ohms |
| Actuator Speed: | 0-33 in/per sec. (0-150V) |
| Cooling: | Fan forced air |
| Dimensions: | 9”W X 15”H X 20”D (229mm) (381mm) (508mm) |
| Weight: | 35lb (16kg) |
Chapter 02 / 03
What the 858 Welds
The 858 handles applications that conventional welders can't:
Thermocouple wire welding — Type K, J, T, E, N, R, S, B, and exotic thermocouple alloys. Junction welds with no contamination, no filler, and millisecond cycle times for reliable, repeatable temperature sensing.
Dissimilar metals joining — copper to stainless, aluminum to steel, platinum to nickel, and refractory pairings other processes won't quote. Capacitor discharge precision means no melted alloy zone, no intermetallic embrittlement.
Fine-wire assemblies — wires from 0.001" to 0.040" diameter, including magnet wire, lead wire, and instrument-grade conductors used in medical sensors, aerospace harnesses, and battery tab assemblies.
Battery tab welding — copper, nickel, and aluminum tabs to cell terminals without thermal damage to the cell or the surrounding pack architecture.
Heater element & resistance wire — nichrome, kanthal, and other resistance alloys joined to lead wire without changing the resistance characteristic of the joint.
Gallery
The 858 on the bench
Power supply, fixture, and the joints they make.
Chapter 03 / 03
Operation So Simple And Intuitive, We Can Show You How To Use it.
If you’re like us, sometimes a picture (or video) is worth a thousand words. Watch our video showing you step-by-step how easy Percussion Welder 726 Bench fixture is to operate.
Where to next
726 Bench Fixture
The 726 Bench Fixture is the “weld head” of the MTI Percussion Welder system. When combined with the Model 858 Percussion Welder the system provides everything required for producing consistent, reliable weld joints. Call us on 303-536-7838 for more details.
Open →Percussion Weld Monitor
The Percussion Weld Monitor provides waveform analysis to aid in the development of weld settings, define a "signature" waveform for any particular product, evaluate production welds, and collect data to meet your QC requirements. Call us on 303-536-7838 for more details.
Open →Actuator
The Model 808 Percussion Welder Actuator is a solenoid specifically designed for percussion welding, with a low mass of the moving parts, allowing for the rapid acceleration of the weldment held in the moving wire holder.
Open →528 628 858 Upgrade
Product Heritage & Upgrade Path If you're running a Superior 528 or MTI 628 and wondering what's next — good news: the physics hasn't changed. The controls got a lot better. And we still answer the phone. < 3 ms weld
Open →FAQ
What is a thermocouple welder?
A thermocouple welder is a precision welding machine designed to join the two dissimilar wires that form a thermocouple junction (such as Type K, J, or T). The 858 uses capacitor discharge to fuse the wires in milliseconds without filler material, contamination, or heat damage to the wire — preserving the thermocouple's calibration accuracy.
How does a percussion welder differ from a micro spot welder?
A micro spot welder presses two materials between electrodes and passes current through them, creating a fused spot. A percussion welder uses a capacitor to discharge a precisely controlled burst of energy across a small gap, forging the materials together with mechanical motion. Percussion welding produces virtually no heat-affected zone, doesn't require electrode contact pressure, and joins dissimilar metals that spot welders struggle with.
What materials can the 858 weld?
Copper, stainless steel (300 and 400 series), nickel and nickel alloys, platinum, gold, silver, aluminum, titanium, kovar, MP35N, nichrome, kanthal, and most thermocouple alloy combinations. The 858 handles dissimilar pairings that resistance and arc welding cannot.
What wire diameters does the 858 handle?
0.001" to 0.040" diameter, with tooling and process adjustments for thinner or thicker materials available on request.
Does the 858 require operator certification?
No — the 858 is designed for intuitive manual operation with minimal training. For ISO 9001 or AS9100 production environments, we provide operator training, weld parameter documentation, and the optional Percussion Weld Monitor for automated good/no-good quality control.
What does the 858 ship with, and can it run on a production line?
The system is ready to use on arrival and comes with the Model 726 Bench Fixture and the optional Percussion Weld Monitor. It suits manual operation and can be integrated into automated production lines. Call 303-536-7838 to discuss your setup.
Still have a question? Tell us your weld challenge and an engineer will reply.
Start here
Send us your wire, tab or thermocouple pair and we will weld it on the 858 at our Denver lab.
Prefer to talk? Book a demo or call 303-536-7838