How to Prevent Fastener Threads from Galling

If you’re busy on the worksite all day, the last thing you need is problems with installing your fasteners. You may have previously installed a bolt or nut and realised that the thread is damaged or even seized.

This type of damage is often referred to as Galling.

Galling is a common issue when working with fasteners. With some basic knowledge, you can save time and money by using the recommended installation practices.


Firstly, what is thread galling?

Galling typically occurs in the bolt installation process where friction and pressure damages the thread. During the tightening process, the pressure and friction between surfaces causes the fasteners’ protective surfaces to wear down, and in some cases, galling will cause the bolt to seize completely to the nut. If this happens, it is extremely difficult to remove without cutting or splitting the nut.

Stainless steel fasteners are prone to galling, but galling occurs in aluminium, titanium and many other materials.

 

Source: wikipedia


 

How do you prevent thread galling?

Thankfully, there are many ways that you can prevent galling. The best practices include:

 

1) Keeping the nuts and bolts clean before installation.

 

2) Ensuring that fasteners have been stored away from heat. 

As mentioned above, increased heat is correlated with galling.

 

3) Inspecting the threads before installation to ensure they are not already damaged.

 

4) Installing the fastener gradually and slowly to decrease friction and heat.

Using a high speed driver and/or impact wrench is not recommended as this can break the thread.

 

5) Using an Anti-seize product to lubricate the threads.

We highly recommend investing in quality lubricants as this is one of the most effective prevention methods. There are many different options on the market, with different strength grades designed for different materials and environments.


What is Anti-seize?

Anti-seize is specifically applied to fasteners, bolts, flanges and related products for the prevention of galling, seizing and can be used in disassembly also. Anti-seize is typically applied to the bolt or stud thread, the face under the bolt head, the nut head or washers. Note that it’s important to choose the correct anti-seize product for your needs. Each product is formulated for specific applications (e.g. stainless steel, copper, nickel) so read the label before use and contact one of our team members for expert assistance.

Konnect offers several of these products from leading brands such as Chemtools, Loctite and CRC - check them out here.

 

6) Mix and match the fastener material grades.

There have been reports that using a mix of a soft and hard grade material is a good way to prevent galling, although this may not be appropriate in all environments such as those with harsh conditions that have specific material requirements.

 

7) Work with a quality fastener supplier.

For obvious reasons, the quality of the fastener is dependent on the manufacturer, therefore we suggest working with reputable suppliers with stringent quality control standards.

 

Remember, it’s better to be proactive by preventing galling than having to cut or break the fastener, which can lead to wasted time, money and potential damage to other parts secured to the hardware.

 

We hope you have found this short article useful and we’d like to hear from you in the comments.

Tell us, what methods have you used to prevent thread galling?

Have you experienced galling when working with fasteners?