Thread galling is a serious problem that can affect the design, strength and performance of fasteners, bolts, screws and other threaded metal components. It occurs when two metallic surfaces are forced into contact and then scrape or grind against each other while they are attempting to slide over one another. It causes a bump, ridge or crater on the surface of the component, and it makes the materials stick together and seize. In some cases, it can even cause the pieces to rust together and fail.
While galling is an unavoidable symptom of the way that metallic parts are engineered, it does have many preventative measures that can be taken to decrease the chance of it occurring. One of the most effective is lubrication. Lubrication reduces friction between the surfaces of a nut and bolt, and it also helps to dissipate heat, both of which can cause galling. In addition, lubricants can help to minimize the risk of corrosion between different materials.
Most metals produce their own natural oxide layer to protect them from detrimental corrosion, but this film breaks down during installation pressures, which can lead to galling. This is especially true for metals like stainless steel, aluminum and titanium, which can produce an oxide layer that is more prone to galling than other materials.
Another common cause of thread galling is high installation speeds. This can create very high temperatures on the flanks of the metal that are in contact with each other. This can quickly cause the material to transfer from one piece to the other, resulting in cold-welding and eventually causing the threaded fastener to seize.
In addition to installing fasteners at a slower speed, it’s important to keep the fasteners clean and free of debris. This will minimize the amount of friction generated during installation, which can lead to galling. Additionally, deburring the threaded fasteners can help to smooth out rough edges, which will also reduce the friction between the metal surfaces.
Lastly, it’s a good idea to use different metal grades for mating fasteners. This can reduce the likelihood of thread galling, as the different metals will have varying corrosion resistance.
All of these prevention tips can greatly reduce the chances of thread galling, which is a significant issue that can affect the longevity and efficiency of your fasteners. Taking the time to implement these simple prevention methods can significantly reduce the chances of galling, and it can also increase the longevity of your bolts, nuts and other fasteners. For more information about thread galling or for advice on choosing the best fasteners for your application, please reach out to the experts at MarshFasteners today. We are a leading supplier of stainless steel fasteners and can offer expert guidance on all your nut and bolt needs. Contact us online to get started. We look forward to hearing from you..