Stick Electrode Codes

Typically, a four or five digit code is printed directly onto the side of a stick electrode. This code contains valuable information, so it is prudent to learn how to read it. The code is based on a standardized system developed by the American welding Society (AWS), and is used by nearly every electrode sold in the United States. However, the welding enthusiast preparing to purchase stick electrodes should be aware that some manufacturers add their own codes as prefixes or suffixes to the main code, so if there are more than five numbers, take care to determine which are the AWS code and which are additions by the manufacturer.

Often, though not always, an “E” is placed in front of the AWS electrode code. This has no real significance, since it only denotes “electrode,” and can be ignored. The next two or three digits indicate the tensile strength of a correctly-made weld that uses the electrode, in thousands of pounds per square inch (psi). Whether there are four or five digits in the complete code depends on whether the tensile strength is in the tens or hundreds of thousands of psi.

For example, if there are four digits and the code’s first two numbers are 45, then the weld’s tensile strength will be 45,000 psi when it is correctly laid down. If there are five digits, and the code begins with 120, then the potential tensile strength is 120,000 psi. The code is easy to decipher because if there are four digits, then the psi is never greater than 99,000 psi; if there are five digits, then the psi must be 100,000 or over.

The number immediately following the tensile strength code – which is in the third position if the psi is 99,000 or under, meaning a four-digit code, or in the fourth position if there is a psi of 100,000 or more, making a five-digit code – is a special code indicating the positions that the stick electrode can be used in. There are four possible numbers for this part of the code, from 1 to 4:

1.    This stick electrode can be used in every welding position, including overhead, vertical, horizontal, and flat.

2.    The stick electrode bearing a “2” can only be used in flat position groove welds, such as flat and horizontal fillet welds.

3.    A stick electrode marked thus can be used only in the flat position.

4.    Flat, horizontal, and vertical downward positions are possible with this stick electrode, but it cannot be used for overhead welds.

The final number of the code shows what chemical is used in the electrode’s flux sheath. This will help determine such matters as the substance it can be used to weld, the penetration depth of the weld, which of the four available current types can be used with the electrode, and what kind of slag will be left behind on the weld bead surface.

Additional suffixes can also be printed to indicate the filler metal of which the stick electrode itself is made – these may take the form of a numerical code, the AISI identification number of stainless steel, or the chemical composition of an alloy in lettering based on the periodic table of the elements.