Blind rivets: Technical explanations
The rivet shaft is the element which makes the connection
The rivet shaft is formed by the rivet mandrel and remains in the component on a permanent basis. The shaft type selection is made on the basis of the grounds of
- - the expected mechanical stress,
- - the required anti-corrosion performance,
- - the component layout,
- - the temperature stress and partly also on
- - the visual impact.
The rivet mandrel is needed for shaping the rivet shaft
The mandrel selection is based on the shaft type and on the requirements with regard to processing and operating properties. In order to enhance the rivet’s shearing force, some rivet types use a capti ve mandrel which remains in place after the connection has been made.
The principle of the setting process
Together with the mandrel, the blind rivet is inserted into the setti ng device and introduced into the rivet hole.
The rivet mandrel is pulled by triggering the stroke with the help of the clamping jaws. The mandrel head reshapes the end of the rivet shaft. When the rivet head is fl ush with the component surface, the process is completed.
In this position the forces increase and the mandrel fractures on the predetermined break point. The spent part of the mandrel is removed and the captive mandrel remains in the shaft.