Avoid a Galls-Up
Announcement posted by Anzor Fasteners 16 Oct 2015
An issue to avoid with stainless steel threads Cold-Welding on bolts
What is stainless ‘galling’?
Galling is when two threads bind together and seize. It can be fairly common when using stainless steel fasteners. This seizing, galling or ‘cold-welding’ of stainless threads can result in fasteners having to be cut away as un-threading is impossible.
When is galling likely to occur?
- With larger threads of stainless fasteners – say M10 and up – this is because of a greater surface contact area, therefore more friction occurs in installation, causing heat, and binding. But note that there is a risk of all thread sizes galling.
- Nyloc Nuts – the nyloc causes pressure between the threads, again causing friction.
- When the thread is under load –say a turnbuckle tightening wire.
- Dirt in the threads.
- Installing too quickly – have a look at this video illustrating this point – watch until 1:10. (Note Anzor does not stock the product this video promotes).
How to avoid galling?
Anzor is pleased to launch its new range of Stainless Thread Lubrication products:
- When it comes to choosing a lubricant, it is important to use a Nickel based stainless lubricant or a lanolin based lubricant, i.e. something that won’t react with the stainless steel. We stock Loctite 771 a nickel based lubricant specifically for stainless steel threads: We also stock Lanotec – a lanolin based lubricant, and Tef Gel which also prevents galling.
Also make sure you:
- Remove particles and dirt from threads.
- Moderate the installation speed to a low rate of RPM. If the threads are lubricated, you may be able to install at a higher RPM.
Good luck with your threading. For more information on galling, please see this article by ASSDA: Galling by the Australian Stainless Steel Development Association.