In the general family of fasteners, rivet is considered one of the most reliable fixation options. It is distinguished by the possibility of forming a closed fixing ligament, which determines the strength and durability of the connected structure. Another thing is that the use of the through principle of fastening is not always technically permissible. However, there are different types of rivets that differ in design and other characteristics, which allows you to effectively use them in a variety of areas.
Key Features
From the point of view of choosing this hardware, the main characteristic is size. Several parameters are taken into account, among which are the diameter of the rod. It can be from 1 to 36 mm with a length of from 2 to 180 mm. At the same time, you should not think that a large thickness is directly related to the strength of the rivet. Steel rod parts with a thickness of 10 mm can be much stronger than copper tubular elements, the diameter of which exceeds 20 mm. However, a lot depends on the nature of the exerted loads - sometimes it is more profitable to use thin-walled tubular parts.
Models of rivets with a low semicircular head just have a small range of thickness indicators - from 1 to 10 mm, and the length in this case varies from 4 to 80 mm. Products with a flat hat have a thickness in the range of 2-36 mm with a length of 4-180 mm. The longest details are semi-blind types of rivets that can be used in niches with a depth of about 200 mm.
Design Classification
There are many versions and modifications of this hardware. The standard is a spacer element that is used in the combination of loose, soft and fragile building materials. The reverse head of this rivet is folded during installation, which allows you to distribute the load over a large area from the back. To work with wood, petal models are used. At the time of installation, the rod opens and forms petal folds, which, in turn, give back emphasis and fixation of the material. As a rule, these are aluminum rivets that can cope with lightweight panels. Multi-clamping products intended for joining materials of different thicknesses are also interesting. The formed unit in this case is universal, therefore it is often used where there is no clear idea of the size of the workpieces. The most technological option is offered by the developers of cassette models. In this design, the locking stop elements can be represented by dozens of levels. In this case, only one rod will act as the supporting base.
Material classification
Most rivets are made of metal. In particular, aluminum, steel, brass and copper are used. Almost all models of this type have high corrosion protection requirements. Aluminum and copper rivets are also characterized by ductility and light weight. Steel fasteners are often used in structures where it is necessary to ensure sufficient strength.
The use of plastic rivets is also common. They are mainly made of polyamide, which is also able to provide strong joints. Of course, in terms of strength, this option will lose to the metal. But if galvanic stainless rivets in the long term are not able to guarantee consistently high protection against moisture, then plastic does not initially enter into destructive reactions with such contacts. In addition, polyamide does not conduct electric current and optimally interacts with materials made of composites and fiberglass. Today, technologists are developing methods for hot bonding plastic rivets and fixed composite materials, which completely creates a monolithic structure.
Extraction and threaded rivets
The presence of thread makes the rivets related to other hardware, but in this case the method of double-sided fixing is implemented. That is, the element body is embedded in the prepared hole, after which the second part of the sleeve is introduced from the other side by twisting. This method has its advantages in the form of reliability and ease of implementation, but it can not always be implemented. Therefore, more often use exhaust models. If threaded rivets require twisting of the auxiliary element to ensure rigid fixation, the exhaust principle implies deformation of the structure at the end to create a stop. This may be the aforementioned expansion principle, and the thickening of the tubular structure, as well as other methods of deformation of the tip of the rivet in order to secure it.
Installation technique
The operation is performed in several stages. First of all, a hole is created with a drill, along the line of which the part will be inserted. Almost all types of rivets should be installed in niches whose diameter is 10-15% greater than the thickness of the rod used. The density of entry in this case does not matter. Fasteners are integrated into the prepared hole so that its head is located on the back side of the working surface.
Installation approaches may vary at this point. Threaded models can be fixed with your own hands, without the use of a special tool. However, steel rivets of explosive type or spacer hardware are deformed only with the help of special devices. Riveting is done with electric drums or a piston hammer, it depends on the type of fastener.
Where is rivet applied?
Mostly this fixture is used in the construction industry and repair work. Massive constructions cannot be connected with this technology, but decorative decorative materials in the form of panels, sheets and plates are often fastened in this way. Manufacturability and accuracy of fixation allow the use of such hardware in production. For example, aluminum rivets reliably connect wood chip panels. Steel elements are used on machine-building conveyors when installing metal sheets and parts.
Conclusion
The double-sided clamping method has many advantages over other fasteners. But he has his own flaws. The fact is that most of the clamps of this type are not designed for dismantling. For example, explosive types of rivets can be called disposable - in the sense that they can only be installed in one place without the possibility of reinstallation. This fact is important not so much economically as technically - as the nuance of constantly equipping the target part with hardware. It will be possible to remove the rivet only by deforming the products to be joined, but even in this case, further rivet connection with the removed hardware will not be possible.