The rate at which electrons flow through a current. As the amperage increases, the strength of the electric current also increases. Typically, many weld machines have recommended settings for specific welding applications. Amp selection is a critical part of welding, and may be predicted based on electrode size and composition of the metal being welded. During the back purging process, Aquasol’s Fiback Fiberglass Backing Tape is able to accommodate from 0-600 AMPS. The 200 AMP is ideal for lightweight thinner materials such as aluminum, while the 600 AMP is well suited for dense metals, like carbon and stainless steel which tend to be thicker gauge metals.