Any recommendations for replacements that will not rust? Doesn’t anyone make stainless steel ones??
Stainless steel nuts are available from a number of suppliers. As usual Google is your best friend. As an alternative you can buy caps in various finishes which will conceal the problems. You just have to have the special tool to remove the cap before you can get to the actual nut. If you do replace the nuts just make sure you get the correct thread and seat specification.
I got hold of a set of secondhand genuine chrome wheel nuts. They were from my local MX-5 breakers here in Derbyshire. I was fortunate enough to buy them on eBay then go select my own from their stock.
Can be a bit iffy if you order unseen off eBay, these type of nuts can end up looking worse for wear if not cleaned regularly.
I cleaned my eBay purchased one’s up and fitted them, look smart on any wheel.
And yes they fit all models MX-5 that came with Mazda fit alloys.
The price new can be over £5 each.
Stainless Steel threads have a habit of galling. Most St Stl wheel nuts just have a pressed cover on them.
I had assumed the NDs used exactly the same domed chromed wheel nuts as used on all other MX5s. The OPs look like aftermarket.
From recollection, there were two types, one slightly stubbier than the other. On a MX5, the stubby one would split on the top. I assume it was for a 323 or something.
I think there would be some metallurgical reasons why you would not want stainless steel nuts on a steel stud (expansion rates?).
Because the threads gall.
For those not sure what “galling” is; seized nuts due to damaged threads.
Also, I guess the torque specs change. To what, I don’t know.
Many none corroding materials are none corroding because they have an oxide film. Stainless Steel, is one of them in its many guises.
Galling is when the pressure between components is sufficient to break down that oxide coating or protection. With the parent metal exposed the high points, which at a microstructural level, there are many, create heat and abrasion. This can be sufficient to weld the materials together, again at a microstructural level.
To the visible eye, it can frequently look like the material has rolled off or torn. Bottom line is seizure, stripped threads and sheared fasteners.
As a young man my dad always said that if I cleaned my nuts on a regular basis they would last a lifetime and always perform their allocated duties in fine style no matter how arduous the conditions might become. The same goes for the ones on the car!!!
stainless steel is less strong compared to tempered (high tensile strength steel).
go for normal steel chromed nuts they are better safetewise
You would not change torque settings. The torque figure is designed to create a certain tension in the fasteners. In this case, in the studs, giving a clamping force between the nut (in the case of studs) and the hub face which holds the wheel in place through static friction. Changing the torque figure, and in particularly loosening it would lead you into a problem. One of the issues when alloy wheels first became popular was that the very structure on the aluminium allowed for the material to creep and so, over time, relax the tension in the fixings. Steel was not prone to this.
The locking or holding friction of a nut, conical seat in this case, is between the cone on the nut and the female come in the wheel. You should never grease them as they can have a very significant effect on the tightening torque and thus the induced stress in the studs. This can result in stress fractures at the roots of the threads and eventual shearing of the studs. It is why you should never tighten a wheel nut “FT” or “full ugger duggers” Also the popular internet concept that spigot rings support the weight of the car is also very wrong.
Most wheel nuts are not high tensile, they do not need to be.
The reason Chrome finishes fail is Chrome is very brittle. When tightening / loosening the point load forces of the “spanner” mean the substrate steel deforms and the chrome finish fractures. Moisture ingresses and corrosion happens.
Yes, they don’t look like factory wheel nuts at all. What did the 30th AE come with?
They look different to the “usual” Mazda wheel nuts. Maybe because of the RAYS wheels.
They came with the standard chromed 17mm that were fitted to all MX5s at the time.
As you say those do not look like ours.
Is that the wrong picture? those ain’t Rays.
I see, Rays nuts not wheels. So were both right, or is that wrong!!!
