Rivets are generally classified according to their appearance. The rivets are classified based on the diameter of the cylinder, the length of the cylinder and even the raw material and construction material. But in any case, the greatest diversity defined for this tool is apparent diversity.
In the case of materials, it is recommended that the rivets and the parts in question be of the same material, so different materials such as aluminum, steel, copper and other metals are used to make rivets. For example, in wet areas, stainless aluminum rivets are used. Also, in the case of the material, it is better to use wider head rivets with a wider cap when the material of the piece is softer than the nail; Or, before deforming the nail cylinder into the cap and riveting, the washers were helped to fit between the soft part and the end cap.
Also, in the case of nail length, if the length of the nail cylinder is more than the required amount, since the need to cut the excess amount, the riveting process will be longer, the cost price will exceed the standard. And more energy is spent, and at the same time with all this, a proper and quality connection may not be made. If the length of the cylinder is short, the connection is not strong enough.
Appearance of rivets:
Using this type of rivet is one of the oldest, simplest and safest connection methods. The rivet refers to the solidity of the cylindrical part of the nail. Solid nails are used for connections with high reliability. Of course, this type of rivet is used only when there is access to both sides of the desired parts.
Semi-hollow rivets are the same as the previous model, except that their overall cylinder is hollow and requires less force to be riveted.
Hollow or blind flags
The hollow rivet is made of a nail and a chamber-like cap. This rivet is inserted into the hole on the work piece from the chamber and then the riveting machine, while pulling and pressing the parts together, changes the shape of the cap and makes the connection stronger. Subsequently, the pressure of the device breaks the remaining nail and only a small part of the chamber remains without any appendages on the piece. The good thing about this is that due to the function of the blind or hollow rivets, you do not need to have access to both sides to work with them. Also, the speed of action in working with these rivets is high. But at the same time, you can not expect a long life from these rivets because they are not resistant to corrosion. Therefore, they are not used for sensitive tasks and tasks that require high reliability.
The emptiness of this type of rivet can also be detected from its cap. In fact, the cap is made in the shape of a hollow ring because the rivet is empty and there is no cover for it. This type of rivet is used for lightweight and non-metallic works such as leather, plastic and cardboard. To connect this type of rivets, a mandrel is used to form it by tapping it.
Fungal rivets are used when the parts are thin and one side of the work needs to be perfectly smooth and without protrusions.
Depending on the material and diameter of the cylinder, explosives are placed in a small, sealed chamber at the end of this type of rivet. After inserting the rivet nail into the hole created on the parts, the nail tip is gradually heated with a hoe. As a result of this heat, the explosive explodes at a temperature of 120 to 130 and the desired lock is created on the connection.
Blind Riveting or blooming nails or special blind
Because this rivet, due to its shape and function structure, distributes the applied pressure on the surface and does not concentrate the pressure in a specific part of the surface, it is suitable for soft surfaces. Soft plastics and a variety of foams are of this type. Sprayers are also suitable for large cavities, covering a wider area.
Impact or hammer rivet
Hammer blades are used for metal plates and parts in industry. These types of rivets are used both cold and hot and have a variety of caps.
In the end, it should be said that in addition to the types of rivets mentioned, there is another criterion for the apparent classification of rivets, and that is the shape of the nail cap. Flaps with a rounded head or flat or cap caps can be called belt flaps, flat semicircles, semicircles, lenses, and cap pins. Also, the fact that the rivet cap has two or more steps, the angle of the cap of the cap and the degree of contraction and width of the cap are the criteria in their appearance and naming their type.