Projection Welding of Fasteners to Hot Stamped Boron Steel

Weld Systems Integrators has proven results and welding solutions to tough-to-weld materials and applications.

Projection Welding of Fasteners to Hot Stamped Boron Steel. Capacitor Discharge from Weld Systems Integrators (sometimes referred to as Capacitive Discharge) stores energy for extremely fast release of energy with large peak currents. More energy into weld formation and less into heating the surrounding material. The heat affected weld zone, where the properties of the metal have been changed is smaller, minimizing changes in the metallurgy of the workpiece.

Weld Systems Integrators manufactured our first Capacitor Discharge Resistance Welder in 2007. That CD Welder is still in production today making great welds and great parts. Through the years, we’ve had OEM’s, Tier 1 and Tier 2 suppliers bring parts to our Welding Lab and we have demonstrated consistent results.

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Capacitor Discharge Welding | Weld Systems Integrators


  • Fasteners are extremely soft compared to the base material.
  • Hot-Stamp Materials develop AlSi coating in the furnace.
  • Resistive qualities of AlSi coating are inconsistent across the part.
  • Short Weld Times called for in projection welding makes it difficult to deliver enough heat to the base material, often vaporizing the projections without welding.
  • Consistent projection welding is difficult with most processes, and even with many Capacitor Discharge Welding machines!
A M8 nut welded to 2-mm boron.A M6 nut welded to 2-mm boron.


WSI has over 10 years of proven results with tough-to-weld applications, like projection welding fasteners to Hot-Stamped, High-Boron AlSi-Coated parts! WSI Capacitor Discharge Welding Welders can make good welds 100% of the time.

Capacitor Discharge Welding Process:
  • Low primary power requirement, relative to resistance welding.
  • No Peak Energy Billing.
  • 99.9% Power Factor means virtually no wasted welding current.
  • Very fast weld time (typically under 10ms).
  • Ultra-Fast Rise Time welds fast while minimizing heat-affected zone (HAZ).
  • Tooling Often Lasts 3-5 Times Longer than other processes.
  • Maximum current draw of 30 Amps for the welding process.
  • 60 Amps or less Single-Phase Primary Power required for a complete machine.
  • 100,000+ Peak Amps in under 5 milliseconds.
  • Fast Follow-up Design allows for instantaneous response to weld set-down.
  • No Water Cooling Required for Power Supply and Control. Tooling may require minimal cooling depending on final specifications.
  • Fully-Monitored for Process Confirmation and Maintenance.
  • Easy to use HMI User Interface.
  • Robust, Reliable, Consistent Process.
  • Welds with WSI CD Welders can achieve up to 200% Required Torque and Push-Out Values.
  • Over 10 years of Consistent, Proven Results.
  • WSI CD Welders are designed around customer applications, and are not ‘cookie-cutter’ machines.
  • Specifications are determined by WSI engineers in WSI’s own welding lab, setting the standard for the industry.
  • WSI CD Welders are designed for safe, easy operation by human operators, or for ease of integration into robotic cells. Controls, safety circuits, and guarding are engineered to customer specifications.
  • WSI Single, Dual, or Multi-Head Welders are easily integrated with nut/part feeders, and are perfect for nut farms, and other high-density manufacturing operations.
WSI Capacitor Discharge Welding technology can be applied to a number of applications

A. Steel:

  • Mild and Stainless
  • Tempered and Hardened
  • TRIP (Transformation-Induced Plasticity) and DP (Dual-Phase)
  • Cast
  • Sintered
  • Hot-Stamped High-Boron Steels (like USIBOR®)

B. Coated Metal:

  • AlSi-coated hot-formed parts
  • Zinc / Tin Plated & Galvanized

C. Non-Ferrous Metal:

  • Aluminum
  • Copper
  • Brass
  • Other Metal Alloys

D. Heat-Sensitive Joints – Close Proximity to:

  • Electronics
  • Low-Melting-Point materials like plastics
  • Paint / Other coloring
CONTACT Weld Systems Integrators for more information on WSI CD Welding solutions. For immediate assistance, please feel free to give us a call at 844-WSI-WELD.