fischer nylon expansion plug

What it is

The fischer expansion plug is a nylon wall plug, also called a dowel or anchor, that lets a screw hold firmly in masonry, concrete or other solid building materials. Artur Fischer, the prolific inventor from the Black Forest who founded his one-man company in 1948, filed the patent application for the nylon expansion dowel on 7 November 1958. He had patented an earlier sleeve-shaped expansion dowel in 1956.

How it works

The plug is inserted into a drilled hole. As a screw is driven in, the two halves of the plug spread apart and press against the walls of the hole. Locking tongues and teeth stop the plug from turning, while sawtooth-shaped edges grip the surrounding material and strengthen the connection. Fischer carved his first prototype from a single piece of nylon. Before this, wall fixings were usually metal or improvised from wooden plugs and hemp.

Why it stands out

The nylon plug made reliable fixings fast, cheap and simple for professionals and amateurs alike. It became one of the best-known products of German engineering and the foundation of fischer's fixing systems business. Artur Fischer himself became one of the most prolific inventors of his time, with an enormous number of patents to his name, including an electrically triggered camera flash and the fischertechnik construction toy.

Where you meet it

Look behind almost any shelf, mirror, cabinet or curtain rail fixed to a solid wall and you will probably find a plastic plug descended from Fischer's design. The grey fischer plug is a standard item in hardware stores and on building sites around the world.