United States501 South Cedar Lane / P.O. Box 418 / Greencastle, PA 17225

Harbert's Products, Inc.

Servicing Canada, U.S.A & Global

800-377-3103

717-597-1717

ISO 9001:2015 Certification for Quality Management

What Is Slag?


The slag that is produced by submerged arc welding when the granulated flux that blankets the molten weld puddle melts and solidifies as it cools. Once the weld is made, what remains is the slag and the unused flux that did not melt and solidify into slag. These materials can be collected in different ways, depending on the company making the welds and their process. These processes are listed below.

  • All hardened slag and unused flux is discarded after the weld is made.
  • The hardened slag and the unused flux is manually separated (sifted). The hardened slag is discarded and the unused flux is returned to the system to be used on future welds.
  • The unused flux is collected by a flux recovery system and returned to the system to be used on future welds. The hardened slag is discarded.
What Is Slag?
Harbert’s can reprocess both hardened slag only or hardened slag and unused flux together. Customers do not have to alter or change their collection process to accommodate a reprocessing program.