WHAT IS A RIVET ?

The rivet is an attachment element employed in permanent unions, consisting of a cylindrical body and a head, manufactured in aluminium, brass or copper. It is used to make permanent fixations of two or more parts with large scale of employment in the manufactures of aircraft, ships, plates and the manufacture of aluminum utensils.

As for classification, the rivet is categorized by the type of head, being the types: wide and narrow round head, dull and narrow head, and tapered cylindrical head. Round-head rivets have high strength and due to these are used in the metallurgical industry. Flat-minded boring heads are opted in situations where unions that do not allow any kind of bulge on the surface, the narrow-minded heads are more chosen for surfaces where there can be protrusions. The cylindrical head can be used for fixing plates up to seven millimeters thick. Rivets can still be determined as to their specifications, being: the type of material, head type, body diameter in millimeters and useful rivet length.

The riveting process can be accomplished by three distinct forms, depending on the width and effort of the plates, to which they are subjected to be described. These are the processes: riveting by recovering, riveting by simple recovering and double recovering.

Riveting by recovering is widely used in the construction of beams and metallic structures that need to withstand a lot of weight.

Figure 1: Riveting by recovering.

Source: CTISM.

In the riveting of simple overlap, the two plates are joined by a third that is placed on it. Rivets are placed in a zigzag pattern. This type of riveting is widely used in the construction of steam boilers, compressed air tanks and other products that need to ensure the complete sealing of the junction. Double overlay riveting is made to create the perfect seal of the Union of two plates. It is made by joining two plates and placing a plate on each side of the junction. This technique is widely used in the production of chimneys and lamps.

Figure 2: Riveting by double recovering.

Source: CTISM.

At last we will address the fixing of rivets, the same can be divided into two classes: manual process and mechanical process. In the manual process, the fixing is hand-made with the aid of a hammer, cap, against cap or a puller. The mechanical fixation is carried out by means of a pneumatic hammer or pneumatic and hydraulic riveting machines. The hammer is connected to an air compressor, through pipes, flexible, and operates at pressures ranging from 5 Pa to 7 Pa.

References:

COLLINS, J. Projeto mecânico de elementos de máquinas: Uma perspectiva de prevenções de falhas. São Paulo: Editora LTC, 2006.

FRANCESCHI, Alessandro, ANTONELLO, Miguel Guilherme. Elementos de máquinas. Santa Maria. CTIM, Rede E-Tec, 2014.

<http://www.leroymerlin.com.br/rebites-e-acessorios-de-fixacao> Acessado em 13/10/2017.