The numerical designations printed on each welding rod available on the market assist us in making an informed decision. For the purposes of this article, we will limit the electrode selection to the shielded-metal arc welding process (SMAW), more commonly known as “stick” welding. The criteria for selecting welding wires for GMAW (MIG) welding, FCAW (Flux-core) welding, and GTAW (TIG) welding share many of the same fundamental principles.
THE FIRST 2 NUMBERS
As per AWS designation, the first two, and in some cases three numbers on the welding rod refer to the tensile strength, i.e., the ability to resist being pulled apart, X 1,000. For example, in the designation 7018, the number “70” means that a well-made weld made with 7018 can withstand 70,000 pounds per square inch (psi) of tensile stress.
A weld using a rod classified as 11018 can withstand 110,000 pounds per square inch (psi) of tensile stress. The commonly used welding rod 6010 is only rated for 60,000 psi.
THE THIRD NUMBER
The third number refers to the position in which you can use the rod. A “1” means that the rod can be used in all positions. A “2” typically means the rod can be used flat and horizontally. Number “4” is restricted to the flat position only.
THE LAST NUMBER
The last number in the sequence refers to the class of rod or any particular distinguishing characteristic, especially the flux coverings. For example, on a 7018 welding rod, the “8” means that it is a low-hydrogen rod with basic flux covering.
The “0” in 6010, 7010, and 8010, are a class of “fast freeze” with cellulosic flux covering (meaning the molten weld puddle solidifies very quickly), making it well suited to out-of-position welding jobs. The “1” in the last number of 6011 is very similar in characteristics to 6010 but is used on AC power sources.
For the low alloyed welding electrodes, the designation may also include the alloy content in the last digit like in the case of E7018-A1 which means that the electrode contains 0.5% Molybdenum and so on.
So now that we have a baseline understanding of what the numbers mean and how to read the numerical designations of various welding rods on the market, let’s discuss how to pick the best one for your specific job requirements by understanding the rod characteristics and pros and cons of the more commonly used welding electrodes on the market.