What does these letters and figures 'E6013' represent on the classification of coated electrodes?

E6013 represents the classification of a specific type of coated electrode used in welding. In this classification system, the letter "E" stands for electrode, the first two digits "60" indicate the minimum tensile strength of the weld metal in thousands of pounds per square inch (60,000 psi in this case), and the last digit "13" indicates the welding position in which the electrode can be used (in this case, all positions including flat, horizontal, vertical, and overhead).

Therefore, E6013 electrodes are commonly used for general purpose welding applications and are known for their ease of use, smooth arc characteristics, and good weld bead appearance.

E: Type of coating (basic)
6: Tensile strength (60,000 psi)
0: Position (all positions)
1: Type of flux (cellulose)
3: Coating thickness (medium)