Metal galling occurs when two different metals come in contact with each other and adhere to one another. The condition is very common and can occur in any metal machinery that is exposed to excess friction. To prevent galling, you can reduce the amount of friction by lubricating the metal.
It is a form of wear

Galling is a type of wear that occurs when metal surfaces are subject to high amounts of friction. It usually occurs between metals that have a crystalline structure, such as aluminum and stainless steel. The friction causes heat, which deforms the metals and creates more friction. This can lead to a snowball effect, which can cause the hardware to break or snag.

Galling wear can be difficult to predict, but it can be prevented by using proper lubrication. It is also important to choose a material that is not prone to galling, such as hardened tool steel. Also, it is important to use a lubricant that will not dissolve under pressure, such as PTFE.

It is important to note that galling is not the same as abrasive wear or cold welding, which are similar phenomena. It is actually a form of adhesive wear, a combination of friction and adhesion that causes the tearing of crystal structure in the bulk material.
It is a result of friction

Galling occurs when two metals come into contact with each other without sufficient lubrication. The resulting friction causes the surfaces to stick together and can be hard to remove. Fortunately, there are ways to prevent galling from occurring. These include using proper lubrication, electropolishing, and keeping the parts cool. A good anti-seize solution can also reduce the chance of galling.

Stainless steel and aluminum hardware can be particularly susceptible to galling. They have a natural oxide layer that protects them from corrosion, but this will break under high compressive forces. This will increase the friction between the threaded components, and can lead to seizing.

Manufacturers should also be aware that galling can occur even at lower stress loads. Real energy density plays a role here, as does the structure of the plastic zones around penetrating objects. The higher the energy density, the more material will transfer and the greater the friction will be. This is why it is important to select the right material for your application.
It is a cause of damage

Galling is a severe form of adhesive wear caused by metal surfaces that rub together under high stress. It occurs when the load is large enough to penetrate the self-forming oxide layer covering surface asperities on the rubbing metals and permit metal to metal contact. This process is sometimes referred to as cold welding.

This damage can be expensive and is difficult to repair. It can also cause problems with the performance of a system or even lead to failure. There have been cases of stainless-steel bolts shearing off a race engine during preparation for an important race, costing the team time and money.

The condition can be prevented by using proper lubrication. The correct lubricant can keep the bare metals separated and reduce friction. Additionally, it is essential to select the correct materials for the application. Aluminium and certain types of stainless steel are prone to galling, while fully hardened carbon steel is more resistant to it.
It is a preventable condition

Many types of metal machinery are susceptible to galling due to the high amounts of friction between moving parts. It can also be caused by improper lubrication or metal type selection. Some metals, like aluminum and stainless steel, are more prone to galling than others. Other metals, such as hardened tool steel, are resistant to galling.

Although galling can be prevented, it can still cause major equipment failures and lost production time. It is important for everyone in an industrial setting to understand the causes of galling so they can prevent it from occurring.what is galling