As you can see by these unretouched photos above, McGard lug nuts look great even after 1, 3 and 5 years of exposure. If you were to wipe off the residue from the CASS test, you’d have a hard time telling they weren’t new. Unlike the other brands, McGard lug nuts are designed and built to be used!

We tested our regular and bulge style acorn lug nuts against four competitors(A, B, C and D above) in a CASS (copper-accelerated acetic acid-salt spray) chamber. This test was developed by the American Electroplaters Society to measure the specific corrosion resistance of nickel-chromium platings. It involves subjecting plated parts to a salt solution at a specific temperature, pressure and length of time to emulate exposure to the elements.

Accelerated tests like this are employed by car manufacturers to measure quality and performance. A 22 hr. CASS cycle is considered to be equivalent to one year of exposure in Detroit weather conditions. Before each 22 hour CASS cycle the lug nuts were installed and removed using a lug wrench to simulate normal use.