Cap nuts, also known as crown hex nuts, blind nuts, or dome nuts (UK), which have a domed end on one side. When used with threaded fasteners with external threads, the rounded tip surrounds the external threads to protect the threads or prevent nearby objects from contacting the threads. Additionally, the dome provides a more finished look.
The role of this dome cover is to fasten the exposed part of the outside to prevent moisture or other corrosive substances from entering the inside to prevent rust, thereby improving the service life of itself and the connecting parts.
The main raw materials of cap nuts are: carbon steel (including low carbon steel, medium carbon steel, high carbon steel), stainless steel.
Under normal circumstances, the surface of cap nuts needs to be treated, including some surface treatment processes such as galvanization, nickel plating, chrome plating, and dacromet to make them more rust-proof and improve the service life of fasteners. Among the treatment processes, chrome plating is the best process. The products produced by chrome plating are not only smooth and bright, but also have a longer anti-rust and anti-corrosion time, which is comparable to stainless steel.
There are two types of acorn nuts. One is a low, or standard acorn nut. The other is a tall acorn nut. Tall acorn nuts are wider and taller to protect extra long studs. There are also self-locking cap nuts that have twisted threads in the hex area to create a tight friction fit that prevents the nut from loosening due to vibration.
Cap nuts are mainly used on tires and front and rear axles of automobiles, tricycles, and electric vehicles to fix tires, front, rear, left, and right.