Nuts have internal machine threads, for use with machine thread bolts and screws.
A standard six sided nut.
A tempered medium carbon steel. Zinc plated for moderate corrosion resistance. Grade 8 is stronger than grade 5, and is commonly found in high strength automotive applications.
A hex nut with a nylon ring to resist loosening.
A nut with a built in washer.
A nut with a built in washer which is serrated to resist loosening.
A nut with a built in washer and a nylon insert to prevent loosening.