Exothermic welding is also known as exothermic bonding, thermite welding or CADWELD. It was invented around 1895 by Hans Goldschmidt and refined later by Dr Charles Cadwell. It was first used to weld signal bonds to railroad tracks.

CADWELD electrical connections have become recognised as the ultimate connection for rail, cathodic, power and grounding applications.


The CADWELD process can create permanent bond between copper/copper, copper/galvanized or plain steel, copper/copper clad steel, copper/bronze/brass/stainless steel, steel/steel, molecular bonds with no external or heat source The shape of the mold, its dimension, and the size of the welding material, are all dependent on the items to be welded. In this process, conductors are prepared, placed in a purpose-designed graphite mold, and exothermically welded to produce a permanent electrical connection.

CADWELD connections


The CAD weld have four different features Integrated Weld Metal Package, Colour Coded Weld Metal, Electronic Control Unit, Six Foot Control Unit Lead

Benefits of CADWELD V’s other Connection Types

CADWELD Welded Connections Offer the Following Benefits:

  • Low labor costs and ease of application.
  • Inexpensive, lightweight equipment — saves time and money
  • Current carrying (fusing) capacity equal to that of the conductor.
  • Will not deteriorate with age.
  • Permanent molecular bond that cannot loosen or corrode.CADWELD rebar
  • Will withstand repeated faults.
  • No special skills required.
  • No external power or heat required.
  • Can be checked for quality by visual inspection.
  • Portable system.
  • Exceeds IEEEC 837-2014 Grounding Standard

CADWELD V’s Mechanical Connections

CADWELD Weld Mechanical Crimped Connection
 CADWELD diagram

Mechanical connection diagram

Mechanical connection diagram2

Actual Contact Surface

The CADWELD bonded connection provides permanent conductivity over the whole of the section due to a molecular bonding between the metal surfaces.

IEEEC837 2014 Compliant

The mechanical connection presents a significant difference between the apparent contact surface and the actual surface.

IEEEC837 2014 Failed Compliance

IEEEC 837-2014 Standard Compliance (ERICO CADWELD) exothermically welded connections are engineered to create a permanent bond that withstands repeated fault currents and will not loosen, deteriorate or increase in resistance. The connections are designed to maintain for the life of the conductor and/or installation. It also has a high current – carrying capacity equal to that of the conductor. The melting temperature of CADWELD connection is higher than the melting temperature of copper (1082°C).

Once application has been completed, installers can clearly ensure quality assurance by visual inspection of the new connection.

CADWELD connections2

Where is CADWELD used CADWELD has been the preferred method across many industries but predominantly used for:

  • Rail
  • Grounding and EarthingCADWELD connections3
  • Connecting of cables and tapes/strips
  • Connecting to rebar
  • Connecting to fence posts, pipes and flat steel surfaces
  • Connecting to ground rods and earth grids and much more..
  • Lightning Protection
  • Communications
  • Cathodic Protection

There are hundreds of molds and solutions available off the shelf and custom made. At West Australian Power Protection (WAPP) we can provide the right solution to get the job done right the first time.

For more information call (08) 98451 2199 or email