Acorn nuts are a type of fastener whose name comes from its shape. It is a hex nut with a closed-end, domed top to cover the exposed threaded end. They are also known as cap nuts and dome nuts. Acorn cap nuts are easily removed for maintenance to be performed. They also provide an aesthetically pleasing finished look. Acorn Nuts are available in 304/18-8 Stainless Steel, 316 Stainless Steel, Brass, Chrome Plated, and Nickel Plated finish.