Wire Joining Welding 

Butt welding joins two pieces of wire or pins end to end. Percussion welding is one method for butt welding, and it is used for wire to wire, wire to pin and pin to pin welds.

The process uses a rapid heat source and rapid movement to fuse the two pieces into a clean weld. It needs no solder, filler or flux, and it leaves a minimal heat-affected zone because the heating lasts only milliseconds.

Three joint types cover most wire work, and stranded wire is welded as readily as solid.

• Wire to wire: two lengths of wire joined end to end.
• Wire to pin: a wire joined to a pin.
• Pin to pin: two pins joined end to end.
• Stranded to stranded or solid: butt welding stranded wire to stranded wire or to solid wire.

Joining wires with low columnar strength is another typical application.

Percussion welding is particularly useful for joining dissimilar metals such as steel, aluminum, copper and stainless steel, especially when the wire diameters are small. Our bench videos show these combinations, with their captions:

• 20 AWG soft aluminum wire percussion welded to 22 AWG tinned copper
• Slow motion: titanium wire butt weld
• Two strands of .034" Inconel joined together with the Percussion Welder
• 18 AWG stranded tinned copper wire percussion welded to 17 AWG copper clad steel, with a close-up of the weld
• Slow motion: 22 AWG bare copper wire percussion welded to a 0.100" thick aluminum lid

See dissimilar metal welding and the material compatibility checker.

A wire weld follows four stages, finished within milliseconds:

1. The wire and its mate are loaded to a pre-defined gap.
2. A capacitor-discharge arc forms across the gap.
3. The surfaces melt and the molten ends are thrust together in the percussive phase.
4. The parts bond, with no filler, flux or solder.

Because the heating lasts only milliseconds, the effect on the metal around the joint is minimal.

The welding current can be adjusted to give the strength and quality the wire requires, so the process can be tailored to the wire in use. Parameters are set with the dials and switches on the 858 front panel.

The 726 bench fixture holds the pieces: a moveable wireholder with spring-loaded thrust and a stationary workpiece holder, with Z- and Y-axis adjustment. It is triggered with a foot pedal or hand switch.

For a starting point, our lab database holds 131 weld schedules across 33 materials and 68 material pairs, each recording wire diameter, actuator velocity, delay time, capacitance setting, weld voltage and pulse. They are starting points, not guarantees. Change one setting at a time and validate on your own wire.

The weld joint has low or non-detectable electrical resistance, so there is little or no drop in current flow. The joint has a minimal heat-affected zone and resists vibration.

In pull tests the wire often breaks before the weld. Two bench videos show it:

• 20 AWG brass wire percussion welded to a .015" steel strip, followed by a pull test. The wire broke above the weld at 32 lbs
• 18 AWG stranded tinned copper wire welded to 17 AWG copper clad steel wire, then pulled to failure. Breaks at 46 lbs

These are individual samples, not a specification. Validate strength on your own parts.

For production, the optional Percussion Weld Monitor builds a signature waveform in a Learning stage. In its Test stage it compares later welds against that signature and shows Pass or Fail.

To see your wire welded first, send us the materials. Free applications tests are available, and we can run live, in-person tests at our lab in Denver. Use the material list form or call 303-536-7838.

The video above is our step-by-step demonstration of welding two dissimilar metals together.