The American Welding Society's numbering system identifies an electrode. Through the identification system, the consumer can identify an electrode's diameter, tensile strength, position the electrode is used in and the type of current the electrode can operate under (direct, alternating or both currents).
Some electrodes create stronger welds than others. Tensile strength refers to the amount of pressure that the weld can withstand without breaking or tearing. The first two or three numbers in the name designated to an electrode indicate the tensile strength of a weld it can make (in thousands of pounds per square inch). For example, the E6010 electrode creates welds that can withstand 60,000-psi pressures.
E7018 electrodes are employed when a low level of hydrogen is needed in a weld. These electrodes can be run under AC and DC currents. E6013 electrodes offer a medium penetration and leave a clean weld appearance. E6010 electrodes are ideal for welding on painted, dirty or rusty metals.