The selection of an electrode can be quite challenging as there is ‘no one size fits all’ rod that can be used in all applications. Certain factors can help you with the selection of the best mild steel electrode. Here is all you need to know.
The base metal is also known as the parent metal. The electrode metal should match the chemical and mechanical properties of the base or parent metal.
It ensures a strong and stable weld. So, if the base metal is mild steel, the electrode should also be mild steel or at least a close match. If there is a substantial difference in the match, there is a risk of cracking and other welding abnormalities.
Even the thickness of the base metal is important. If the base metal is thin, you should select an electrode with a soft arc with a smaller diameter and shallow penetration. On the contrary, an electrode with a digging arc and deep penetration power would be a better option.
The tensile strength is another factor to consider in base metal. The tensile strength refers to the breaking strength of a material when it is put under tension. It is the ability of the metal to withstand pressure without breaking when maximum load is put on it. When selecting the electrode, make sure that its minimum tensile strength is similar to that of the minimum base metal. The tensile strength of an electrode is usually printed on the electrode or its packaging.
The welding position is the direction in which the welder lays out the welding bead. The gravity also impacts the flow of molten filler material during the welding position. There are four types of welding positions - flat, horizontal, vertical and overhead.
Most mild steel electrodes are often labelled as all-position electrodes. However, each electrode is qualified for a specific position only, or else it could result in welding issues.
Hence, it would help if you always chose a mild steel electrode that fits the welding position of the application.
Electrodes run on Alternative Current (AC) or Direct Current (DC). AC and DC indicate the polarity of the current in the welding machine and electrodes.
If electrodes are AC specifications, then the polarity will change. If electrodes are labelled DC, then the polarity will remain constant. Electrode-positive has reversed polarity due to which deeper penetration is possible in welding. Electrode-negative has a straight polarity which leads to faster melting of the electrode during the welding.
When you choose a mild steel electrode, you should check for its current compatibility.
There are a few more factors that affect the choice of an electrode:
Type of application
Welding quality and finish
Environmental job conditions
Electrodes are available in varying specification and quality. You should find the best one suited to your welding requirements. It is also recommended to buy them only from reputed manufacturer and supplier brands.