The finish is not a coating (unlike Teflon). It is a heat treatment process in a controlled nitrocarburising atmosphere, and takes several hours, at a specific temperature to produce the desired properties. It is then followed by a post oxidising treatment. This finish gives a dramatic improvement in frictional characteristics, corrosion resistance properties, and fatigue performance superior to those obtained when using hard chromium plating techniques.

A key property of the Nitrotec surface layer is that it has columnar micro-porosity which is capable of retaining lubricant - and so not only is the component hard, but it can hold a lubrication layer. These properties of hardness and intrinsic lubrication together lead to the resistance to wear of the part.

When dry you may see a dark grey slightly patchy mottled looking finish, this is normal, if you wipe the surface with an oily rag you will see how the surface turns a darker black and slowly changes as it absorbs oil into the surface.

Some replacement swivel balls on the market manufactured from distant lands use an incorrect finish of Black Oxide or Chemical Black. This might look nice and shiny but provides little corrosion resistance, no lubricating retention properties, and no additional load bearing fatigue properties.

We're not sure which idiot first described the finish treatment as Teflon, but it has stuck, which is a bit ironic given Teflons properties. You will find lots of webshops describing the finish as Teflon, it's not. So, please when you are buying swivel housings, make sure they really do have a Nitrotec finish - you really don't want a teflon finish- that's great for non-stick saucepans but not so great for swivels!

Benefits include:

• Increased wear resistance
• Improved fatigue performance
• Excellent corrosion resistance
• Indentation resistance
• Weight saving