What Size Welding Rod For...

Here at Engweld, we offer a complete range of welding rods, ensuring welders everywhere have easy access to the right sized welding rods they need for every possible application - all at a great price too. But for those who are perhaps new to welding or are taking on a new job, we want to make sure you can feel confident in knowing you're buying the right welding rod size for whichever job you are planning. As such, we have put together this little guide which goes through all the most frequently asked questions about welding rod diameter sizes, explaining which rod size we would recommend for various applications and material thickness. Choosing the correct welding rod size is a good starting point on the way to achieving a good weld every time, so read on to get the knowledge you require.

What Size Welding Rod Should I Use?

Before we tackle some specific welding rod sizing questions, let's first discuss some general tips that will help you determine the right welding rod size for any future welding applications. The biggest factor in choosing the correct welding rod size from all the different welding rods available is the base metal thickness. In general, a thicker metal will require a thicker welding rod diameter. This general rule of thumb will always suit you right. You should also consider the type of welding process you are planning to engage in, as well as your desired weld joint strength. On top of this, we would always recommend consulting your welding machine manufacturer's recommendations around rod size for specific processes. You can always use a piece of scrap metal to practice if you're unsure.

What Size Welding Rod For 2mm Steel?

If you are planning on welding 2mm steel as your base metal, a welding rod diameter of 2mm or 2.5mm is generally suitable. A thin metal like 2mm steel is often the choice for car body parts and small fabrication projects and a 2-2.5mm welding rod will perform well, making it one of the most popular welding rods with hobbyists who often weld thinner materials.

What Size Welding Rod For 3mm Steel?

With a steel base metal thickness of 3mm, you should consider using a welding rod diameter between 3mm and 3.2mm, which are still some of the smaller diameter electrodes or rods available. This welding thickness is common for working with thicker sheet metal, for example in steel structures or more heavy-duty car components.

What Size Welding Rod For 5mm Steel?

When working with thick materials like 5mm steel, a thicker welding rod diameter is required. We would recommend either a 4mm or 5mm welding rod when welding thicker steel plates like this, often in the construction industry or large-scale factories.

What Size Welding Rod For 6mm Steel?

The steel keeps getting thicker here and we have now reached 6mm. For welding this kind of thicker metal, you'll need at least a 5mm welding rod diameter, or potentially 6mm. This thickness is generally used in heavy-duty steel components, often seen in large structural elements and large machinery frames.

What Size Welding Rod For 10mm Steel?

The thickest material we will cover in this guide in 10mm, which you will only really see if you're engaged in very heavy equipment manufacturing or possible even shipbuilding. For such instances, you need some of the thickest rods available, with either 6mm or 8mm welding rods generally used.

Now we have boxed off some specific material thicknesses and recommended the right welding rod thickness for each, we can look as making some recommendations for different type of welding. We will consider TIG and arc welding projects and recommend the correct filler rod size or welding rod diameter, respectively.

What Size Filler Rod For TIG Welding?

When TIG welding, you will require generally filler rods. Three of the most popular welding rods for TIG welding are ER70S-2, ER4043 and ER309, but what size is right for your application? Generally, the size of the TIG welding filler rod should be slightly thinner than that of the metal being welded. If you are TIG welding a thin metal (up to 2mm metal thickness), a 1.6mm filler rod would be appropriate, or a 2mm rod if you can't get your hands on one a little thinner. Thin TIG welding like this is often seen in electronics welding or thin-walled components in bicycles and motorbikes.

For thicker materials, you'll need thicker electrodes or filler rods. For a base metal thickness over 2mm and up to 6mm, you can use anything around a 2.5mm filler rod thickness and you should achieve the desired result. A general use case would be welding thicker sheet metals or repairing large machinery parts.

What Size Arc Welding Rod To Use?

ARC welding is another form of welding which will require the use of welding rods. It is rather simple to work out which size welding rod you will require when arc welding, however, as the general rule is that the arc welding rod thickness should by the same thickness as the metal being welding. Put simply, for thin metals, choose a thin electrode size. For thicker metals, choose larger diameter rods. You should never use a rod thicker than the base metal and often one slightly thinner than the material being welded will also be suitable in arc welding.

Remember to also always work within the recommended amperage range and consider how welding position may affect your weld.