Acorn nut are hex nuts with a domed top to cover the end of the bolt tip so to protect the thread and provides a finished appearance. The exposed threads should not be longer than the inside height of the cap nut. Like flange nuts, acorn nuts must be tightened with a tool. Eastlo Fastener's acorn cap nut is known for its effecient application performance and endurance widely used in a variety of industries such as construction, manufacturing, engineering, assembling, automobile and so on. The 304 stainless steel provide perfect strength and good corrosion resistance in bad environments like high temperature, cold weather and high humidity areas without the need for time consuming and costly maintenance.