Dowels are used to fix components or furnishings. An extremely important aspect is always the load capacity of a dowel. However, the load capacity is bound to more than just the weight to be fastened. Everything you need to know about the carrying capacity of a dowel, we have summarized here for you.
Typical connection techniques for dowels
You can use a dowel to create a non-positive connection between the component to be fastened and the substrate. There are two different principles of operation:
- Attachment by means of a material bond
- Attachment by means of mechanical force
Attachment by means of a material bond
The fastening of dowels by means of material bonding is one of the connections that can be subjected to the highest loads. A typical example of the anchor with material connection is the chemical dowel, also called injection dowel. First, an anchor sleeve is inserted into the borehole and then injected with a synthetic resin compound.
Depending on the circumstances, it is also possible to inject the synthetic resin mortar without anchor sleeve. Then set the threaded anchor and wait for the mass to set. Under "embed anchors" you will learn the special features of the differences with or without anchor sleeve.
Fastening by means of mechanical traction
Depending on the size and manufacturer, these dowels have a load capacity of several 100 kg. Other heavy-duty dowels, in which a plastic part is compressed, so can carry several 100 kg weight. However, it is a mechanical attachment.
This is how all other dowel types work. Expansion dowels are spread when screwing in the screw, cavity dowels are compressed in a star shape when screwing. When loading, you must also pay attention to how the force acts.
An anchor in a ceiling has tensile force, but a dowel in the wall only loads the anchor laterally, which is why it can virtually support itself. Dowels loaded with traction thus hold less weight than others.
Screw and dowel
The load capacity also depends on how well the screw and dowel match. A larger screw does not necessarily have to be better. Rather, the optimal screw size is crucial. If the screw is too large for a mechanically acting dowel, the load on the mechanically acting area becomes so high that the underlying surface literally breaks away or bursts.
The underground as an essential factor of resilience
We would be already with the actual underground. Of course, concrete with the right dowel has a higher load capacity than a dowel in a porous or sandy subsoil. A firm calculation of the load capacity of a dowel therefore does not exist.
Load bearing capacity and load limits result from various factors
Rather, the load capacity of a dowel in conjunction with the type of dowel, suitable screw, surface, force and weight of the component to be fastened is essentially decisive. Thus, the ultimate capacity is always an experience of a craftsman or handyman.Tips & TricksOn dowel packs you will find a wealth of information about the carrying capacity. From this you can in any case deduce that the load capacity in most cases will be well below the specified values.