The difference between straight polarity and reverse polarity can be confusing. It’s a subject that even professional welders sometimes need help getting right.
Understanding the differences between these polarities is key to identifying which type of polarity you need for your project.
Our goal is to help you understand the differences so that you can choose what’s best for your application.
In this article, I will guide you about straight & reverse polarity in detail, and hopefully, you’ll have a clearer understanding after reading.
Difference Between Straight Polarity And Reverse Polarity
When you have reverse polarity, your electrode will be positive, and your workpiece will be negative. Conversely, straight polarity means that your electrode is negative and your workpiece is positive. If you want deep penetration, then reverse polarity will be best for you, and if you want a better deposition rate, then straight polarity is best.
The difference between both polarities in welding refers to the direction of current flow through the weld pool.
In straight polarity, the current flow’s direction is negative to positive. This is also known as direct current (DC) or single-polarity.
When there is a reversal of polarity, it means that the direction of the current flow has been reversed. This is also known as alternating current (AC).
In the remaining article, I will talk about welding polarities in detail so you can have a better idea.
What do you mean by Polarity?
Polarity refers to the direction of current flow in a circuit. It is usually indicated by a plus or minus sign, with the positive pole being that which has the most potential energy.
In welding, polarity refers to the direction of current flow during the welding process. The polarity of a weld depends on whether it is made with a direct current (DC) or an alternating current (AC).
What is Reverse Polarity in Welding?
Reverse polarity welding is a process that uses the reverse polarity of a welding arc to produce a weld in which the electrode is the cathode, and the workpiece is the anode.
This is done by reversing the polarity of the power supply from its normal position, which would normally cause the electrode to become negatively charged. With reverse polarity, this charge is reversed so that it becomes positively charged instead.
What is Straight Polarity in Welding?
Straight polarity is a welding technique that allows for a weld to be done in one pass. It is used when the weld needs to be continuous and long or when the base metal is thin.
Straight polarity is achieved by using a positive setting of electrode negative and the workpiece positive. This method allows for a smooth arc to form, which is essential in making clean and strong welds.
Difference Between AC & DC Welding
AC and DC welding are two different methods of using a welding machine to join metals together. In this, we will review the main differences between AC and DC welding and their various applications.
AC Welding
AC welding uses an alternating current (AC) power source. The AC voltage is applied to the electrodes in an alternating fashion, which means that the polarity changes at regular intervals.
This causes the metal to heat up and cool down rapidly, resulting in a “weld pool” that’s very small in size (usually less than 1/16 inch). Because of this, AC welding is often used for thin materials that require precision work.
DC Welding
DC welding uses direct current (DC) power sources. These supplies have a constant polarity; they stay on one side of the scale at all times resulting in a larger weld pool than what you would get from an AC supply.
This allows you to make thick joints by moving quickly through them; however, it can also cause problems with arc stability if you’re not careful because there are no breaks between each electrode movement like there are with AC supplies.
Major Differences
| Straight Polarity | Reverse Polarity |
| In straight polarity, the electrode is negatively charged. | In reversed polarity, the electrode is positively charged. |
| Straight polarity gives a hotter arc because it’s easier for current to flow through the workpiece and heat it up. | Reverse polarity gives a less intense arc because there’s more resistance in the workpiece. |
| Straight polarity is when the welding current flows in the same direction as the arc. | Reverse polarity is when the welding current flows in a direction opposite to that of the arc. |
| Straight polarity is used for most applications and produces a bead that’s wider than its height. | Reverse polarity is used when you want to weld in a narrow space or need to fill a gap between two pieces of metal. This kind of polarity tends to produce a bead with a greater height than width. |
| Arc stability is better with straight polarity than with reverse polarity. | The arc length is shorter in reverse polarity than in straight polarity. |
| It’s easier to maintain proper contact with the workpiece during straight polarity because there’s no need for a ground clamp. | The arc voltage is higher in reverse polarity than in straight polarity. |
Why is Straight Polarity Better for TIG/ Mild Steel Welding?
The reason why straight polarity is better for TIG welding and mild steel welding is that it allows you to control the heat input and make sure that you aren’t overheating and burning your metal.
When using a straight polarity machine, you can adjust the amperage so that the arc will be only as big as needed to get your weld started. The rest of the time, it will be smaller so that you don’t overheat or burn your metal.
This means that if you are working with a thinner sheet of metal, you can use a higher amperage without worrying about burning through it too quickly or having to stop in order to let it cool down before continuing on.
If you really want better arc stability during TIG & mild steel welding projects, I recommend straight polarity because it has better arc stability & control.
When to Use Straight Polarity?
In welding, straight polarity is used when the weld joint is not in contact with the base metal. This means that the weld will melt at a lower temperature than the base metal, and so it will not be affected by any mechanical stresses that might cause distortion.
Straight polarity is also used when you want to create a clean, flat bead on an overhead project or on a vertical surface. Moreover, it is recommended to use it for better arc stability and performance during welding.
When to Use Reverse Polarity?
The reverse polarity of the arc allows you to draw more current through the weld, which increases the amount of heat that can be transferred into the joint.
Since pre-heated joints are often cold, this means that reverse polarity will help ensure that your welds have sufficient penetration. It is best to use when you want a deeper penetration in your welds.
I highly recommend reverse polarity for thin metals with low melting points, such as copper.
Conclusion!
In conclusion, reverse polarity is different from straight polarity. I hope this article helped you to get some knowledge about the difference between straight polarity and reverse polarity.
As I told you, straight polarity is basically linked with the negative electrode, and reverse polarity is where the welding wire will be fed in the opposite direction and have a positive electrode.
FAQs:
Is straight polarity positive or negative?
In the case of straight polarity, the electrode is negative & the workplace is positive.
What is the purpose of reverse polarity?
Reverse polarity is designed to equalize the flow of current when it flows through the area of the electrical cable near the material or object. This means many vital components can be used for this purpose without damaging them or causing a fire or explosion.
What are the two types of polarity?
The two types of polarity in welding are straight and reverse polarity. Straight polarity provides better arc stability than reverse polarity.
Which form of current is also called straight polarity?
DC straight polarity is also called DC negative polarity. The current flows in the direction of the positive charge, which is opposite to that of negative polarity. In welding, DC straight polarity is used for arc-starting and strike-start processes.
Is TIG welding straight or reverse polarity?
TIG (tungsten inert gas) welding is done with straight polarity. This means that the torch travels in a straight line as opposed to a circular motion. The polarity refers to the direction of current flow rather than the current’s strength or voltage and therefore does not refer to the hand position on the torch handle when welding with TIG.
Recommended Posts:
