They consist of a threaded portion and a larger diameter section, called the knurl, that is splined to prevent rotation.

The threaded portion may be either male or female.

All of the threaded portion should penetrate the thicker piece.

"Denham Pins" are strong stout wires with a threaded portion in the middle.

And all the threaded portion should penetrate the second piece.

The length of the threaded portion of the plug should be closely matched to the thickness of the head.

Early models had a mono-pod at the stock and a flash suppressor on the muzzle, which was screwed onto a threaded portion of the gun barrel.