Producing shiny nuts takes some fine engineering and great care

Finding high quality wheel nuts to match the quality of your alloy wheels was once a problem. Chrome plated ones look nice on day one but they simply don’t last in the British climate. As soon as a socket is used to tighten them, the plating material cracks and the damage is done. Within a matter of weeks the rust starts to appear no matter how much Vaseline or grease is applied.

Not pretty, not shiny!

We’ve chosen to manufacture all of our wheel nuts from stainless steel because of its rust resistant properties, even though it’s expensive and difficult to machine. 316 grade stainless steel is one of the brightest grades and it also is particularly resistant to salt corrosion - that’s why it’s often referred to as marine grade. External fittings on boats that need to look attractive and remain rust free are typically made from this material.

We reverse engineer the original nut using a Co-Ordinate Measuring Machine (CMM) that measures to an accuracy of approximately two microns or two thousandths of a millimetre. Each feature is measured using the CMM’s touch trigger probe and the exact dimensions are then imported into a Computer-Aided Design (CAD) software program to create a 3-D model of the nut. We have however added a dome-end to our nuts to emphasise the highly polished, lasting shine that’s achievable only with 316 grade stainless steel.

Before our manufacturing process starts we check the incoming wrought stainless steel to ensure it has the correct elemental composition. We use a hand-held X-ray fluorescence spectrometer that has been specifically designed and calibrated to measure the concentration of the eight main elements typically present in stainless steels.

There are two silvery, shiny elements, Molybdenum and Nickel that are typically found at 2.5% and 12% respectively in 316 grade. These two elements are present at lower concentrations in duller grades of stainless steel such as 302 and 304.

We used 302 grade to make some of our early prototypes - but they failed to impress us on the shiny factor, even though they were cheaper to manufacture.

The wrought hexagonal bar is first chopped to length and using a warm forging process, one end of the bar is squashed into a cheese using our own special forging tools. The forging process also makes the stainless steel approximately three times stronger than the original bar because of its effect on the grain structure of the steel.

A 19mm hexagonal stainless steel bar B The cheese after the forging process C The thread and cone end after first machining pass D Finished nut after dome end has been polished

Next the cheese can be machined to the correct geometric shape using a CNC machine that is programmed from the CAD model. The thread is carefully cut before the cone and dome ends are machined. Finally the nuts are loaded into a polishing machine where the dome-end of the nuts are polished to a 0.5 micron finish which gives them a mirror-like finish.

We check a sample of nuts from each batch, using the CMM to ensure that they are dimensionally identical to the original nut supplied by the wheel manufacturer, before they are packed into our attractive custom-made foam insert and carton, ready for immediate despatch from our stockroom.

Now you too can add wheel nuts to your car, and enhance the elegance of your alloy wheels without rust spoiling their appearance. No matter how many times you tighten and remove them, it makes them well worth the extra cost compared to plated nuts.

Pretty and Shiny