Wallplug

A wall plug (UK English), also known as an anchor or "rawlplug" (UK English), is a fiber or plastic (originally wood) insert used to enable the attachment of a screw in material that is porous or brittle or that would otherwise not support the weight of the object attached with the screw. It is a type of anchor that, for example, allows screws to be fitted into masonry walls.

There are many forms of wall plug, but the most common principle is to use a tapered tube of soft material, such as plastic. This is inserted loosely into a drilled hole, then a screw is tightened into the centre. As the screw enters the plug, the soft material of the plug expands conforming tightly to the wall material. Such anchors can attach one object to another in situations where screws, nails, adhesives, or other simple fasteners are either impractical or ineffective. Different types have different levels of strength and can be used on different types of surfaces.

Before commercial wall plugs, fixings were made to brick or masonry walls by chiselling a groove into a soft mortar joint, hammering in a crude wooden plug and then attaching to the wooden plug. This was time consuming and required a large hole, thus more patching of the wall afterwards. It also limited the holes' location to the mortar joints.

The original wall plug was invented by John Joseph Rawlings in 1911, and marketed under the name Rawlplug. These plugs became popular after the First World War, when a demand for retro-fitting existing buildings with new electric lighting coincided with a shortage of labour, encouraging many new labour-saving innovations in the building trade. Rawlplug gained their prominence from their adoption in the British Museum.

Early wall plugs were thick-walled fibre tubes, made of parallel strings bonded with glue.The Rawlings brothers conducted thousand of trials using many diverse materials in their search for the perfect plug. Among the many solutions tested were plugs made of lead, zinc, natural and synthetic rubber, hemp fibres, glass, wood and paper. They imported Indian jute as it possessed natural resistance to the effects of humidity and for particularly damp conditions they developed a range of white bronze plugs. Most current brands are plastic, first designed in 1958 by German inventor Artur Fischer, known as the Fischer Wall Plug.

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