Originally Posted by graysailor
Great. Another project. How can you tell if you have the two piece nuts.
I wasn't able to find any pictures so I'll try to describe the difference.
Two-piece refers to the fact that the steel nut (the part with the threads and the tapered section that mates to the wheel) is wrapped inside a chrome outer shell. The problem with this design is the fact that the chrome outer shell comes loose from the base nut and falls off. When the chrome shell falls off you see the base steel lug nut but it will be a different size (smaller) than the chrome plated outer shell. At that point your lug wrench will be too big and you cannot remove the nuts.
The common fix it to determine your thread size and buy replacement (solid steel, chrome plated) lug nuts. The solid steel lug nuts will be uniformly chrome plated on the exterior surfaces including the tapered portion that mates to the wheel.
The two piece designs can be deceiving and you may think you have solid steel lug nuts. The two piece designs are lighter than solid steel and typically the tapered section that mates to the wheel is not "wrapped" with the chrome plated shell so you'll see the underlying steel lug nut.
Hope that helps.