1969 340 Swinger Chrome Hood Insert Mounting Nuts

There are two types of the stamped nuts used on old cars, so make sure you use the correct type.
Look closely at them.
if it has one notch in the centre hole, if is used on a regular threaded bolt or stud.
if it has two notches in the centre hole, it is a thread cutting nut, and is used on a blank pot metal stud, like emblems, and other die cast parts.