Category Archives: Welding Pinhole Reasons

Welding Pinhole Reasons

There are lots of reasons for pinholes to appear in your welding material. They can be a bit hard to make them disappear completely, but there are some ways to reduce them. Today we are going to be handling this problem with a cause and effect state of mind. An effective way to solve something would always be to know what causes it in the first place. By doing so, we get to the problem immediately without further delay. Hopefully then, we’d know how to remedy it.

The bad thing about pinholes is that most of the time they can be seen with the naked eye, and these are of course considered as a welding defect. This lowers the quality of your weld and also would be a disappointment for your customers. Pinholes are a bit of a nuisance as they can appear in any area of your weld, so you would have to take extra time to check every corner and surface of your finished work. Another problem with pinholes is that they appear at the last minute. This usually happens during mechanical processing.


One of the reasons for pinholes to appear could be traced back to the kind of material that you are welding. The nature of it. Did you know that there are two types of pinholes? We have the hydrogen pinholes and then the hydrogen-nitrogen pinholes. Let’s discuss them further, shall we? It’s good to remember that the nature of the metal you are welding has an effect on the chemical reaction that can happen during the welding. Let’s take for example the hydrogen pinholes. This is formed because of the reaction of water vapor with the elements that can be found in the metal. The water vapor will oxygenate the metal and atomic hydrogen will begin to form, and then this atomic hydrogen will be diffused into liquid metal. During this moment of chemical reaction, the bubbles will begin to form and then eventually will be pinholes.

The next reason would be because of the mold materials. It would do you good to keep in mind that too much nitrogen in your molding will result to an excessive moisture content. Other reasons would be that your material isn’t cleaned properly before welding, or that the slag is not skimmed completely which leads to slag inclusions. The said slags could then be a reason for gas bubbles to form.


So those are the reasons why pinholes appear in your welding material. If you have further questions, you can leave a comment below, or better yet, send us a message. We would really love to clear up any confusion for you. Please feel free to browse around our website and hopefully, you might find something that can be useful to you. You can also subscribe to us so that you will be able to get e-mail alerts in your inbox every time we post something new! Through this, you won’t be missing a single post! Hope to see you soon!