Dowels and their function


Dowels are used to securely fasten components and furniture. The function of dowels plays an important role, because there are various technical types of dowels. Each of these dowels works differently.

Dowels and the various technical designs

Dowels were invented at the beginning of the 20th century. With their help, you can connect building materials or securely connect furnishings to walls, ceilings or floors. This alone makes it clear that there are different operating principles for dowels. Most likely these can be differentiated according to the different dowel types. Here are the most important dowel types:

  • expansion anchor
  • Spring toggle bolts
  • Special dowels for drywall and insulation boards
  • chemical dowels (injection dowels)
  • hollow wall anchors

The requirement for dowels is initially the same regardless of their design. The substrate should be firmly connected to a component or building material.

Function of the expansion dowel

The most commonly used dowel is the expansion dowel. This is also the dowel, which was already patented in Germany in the 1920s. First in metal design, where it is most commonly used today as a plastic dowel. The operating principle is simple: as the name implies, the dowel spreads when screwing in the screw and then sits firmly in the ground.

Function of spring-loaded plugs

Spring-loaded dowels or hinged dowels are used if the substrate has many cavities. The dowel is inserted and then withdrawn slightly. In doing so, two wings unfold, which act like barbs and hold the dowel. This form of dowel is often used especially in ceilings of old buildings.

Special dowels for insulation and drywall panels

Special dowels for insulation boards and drywall panels have a wide cutting "thread". This is screwed into the soft material. As a result, the dowel sits firmly in the material and can not be pulled out without turning. These dowels are often found on the external insulation (ETICS facade insulation).

This is how cavity dowels work

Cavity dowels work on a similar principle as spring-folding clips. They are made of metal. When screwing in the screw, the dowel practically contracts. The sleeve, which has long been cut several times, is compressed and folded in a star shape to the outside. As a result, the dowel sits in cavities whose distances can not be estimated outwardly.

Chemical dowels and their applications

The chemical dowel or injection dowel is also a heavy duty dowel. But it is also used where other dowels fail, because the material of the substrate is not optimal. Even with too large dowel holes, this dowel provides a remedy. For more information, see "Embedding dowels".

Tips & Tricks

Not only the functional principle of the dowels is important. The drilling of the dowel holes is also responsible for how well a dowel sits.


Video Board: Dowels & Pegs