Knurled nut is a type of fastener or nut that features a pattern of ridges or knurls on its outer surface. These ridges provide a better grip and allow the nut to be easily tightened or loosened by hand, without the need for tools.

Knurled nuts are commonly used in applications where frequent adjustments or removal of components are required, such as in machinery, electronics, and automotive industries. They are often made of metal, such as steel or brass, but can also be made of plastic or other materials.

The knurled nut design provides a non-slip surface that allows the user to apply greater force when tightening or loosening the nut. This makes them an ideal choice for applications that require a strong, secure connection that can be quickly adjusted or removed.