Riveting

Riveting

Riveting is a popular method of fastening and joining because of its simplicity, dependability and low cost.
Dissimilar metals and assemblies having a number of parts with non-uniform thickness can readily be fastened.
These joints are made in location where they either do not increase weight of the work at all
(over the weight of an integral work) or increase it negligibly. Structures in which riveted joints are used
may be grouped as: (a) where strength and rigidity are chief requirements, eg, coal bunkers, low pressure
liquid containers, ship hulls; (b) where strength, rigidity, as well as security against leakage should be
considered, eg, boiler drains, pressure vessels, high pressure liquid containers and gas tanks; and
(c) where the joint must resist given outside loads and have sufficient rigidity, eg, bridges, buildings, cranes,
and machine frames. Compared with screwed or bolted joints, riveting requires no additional work or
supplementary parts, such as, lock washers, and supplementary nuts. Compared with welded joints,
riveting makes possible consistently uniform results without resort to X-ray or other methods of inspection.
There are several types of rivets, and some may be solid or hollow; blind rivets are inserted from one side only.
Installing a rivet basically consists of placing the rivet in the hole and deforming the end of its shank by upsetting.
The operation may be performed by hands or by mechanical means, including the use of robots. Riveting may be
done either in room temperature or hot, using special tools, or by using explosives in the cavity of the rivet.

A riveted joint may fail during its service life by tearing, shearing or crushing. On a structure/machine element
a failure of a joint is reported as a failure symptom or mode. This means how the failure is observed. The
causes or cause events that singly, or in combination, may lead to these failure modes, or a general failure
mode, include design related, process related, operation/use related and maintenance related cause events.
The design related cause events include problem of strength analysis, improper selection of the type of joint,
improper material selection, improper size of rivets (shank diameter and length), improper size of rivet holes/
clearance, improper layout of rivet holes and improper size of cover plates/straps. The process related cause
events are improper riveting process, improper riveting environment and defective material (rivet and cover plates);
while operation related cause event is improper loading; and maintenance related cause events include problems of
riveting technicians and improper maintenance of material (including riveting equipment).