What is riveted joints – Forms Of Rivets Head Shapes

APPLICATIONS OF RIVETED JOINTS
A riveted joint is a permanent type of fastener used to join the metal plates or rolled steel sections together. Riveted joints are extensively used in structural works such as bridges and roof trusses and in the construction of pressure vessels such as storage tanks, boilers, etc. Although welded joints are best suited to several of these applications than the riveted joints, however, riveted joints are ideal in cases where the joints will be subjected to pronounced vibrating loads. Riveted joints are also used when a non-metallic plate and a metallic plate are to be connected together. They are also used when the joints are not expected to be heated while joining as in welding, which may cause warping and tempering of the finished surfaces of the joints.
The disadvantage of riveted joints are: (i) more metal is removed while making of the holes, which weakens the working cross sections along the line of the rivet holes, and (ii) weight of the rivets increases the weight of the riveted members.

DIFFERENCES BETWEEN A BOLT AND A RIVET
As a fastener, a riveted resembles a bolt, but differs from it in the shape and the application as well. Although the shape of a rivet is similar to that of a bolt, unlike the bolts, it is used as a permanent fastener to withstand shear forces acting perpendicular to its axis, whereas a bolt is used as a temporary fastener to withstand axial tensile forces.

RIVET
A rivet is a round rod made either from mild steel or non-ferrous materials such as, copper, aluminium, etc., with a head is, and formed at one end during its manufacture and its tail end being slightly tapered. The length of the shank of the rivet must be sufficient enough to accommodate the connection plates and provide enough material for forming a head at its shank end. In general, the shank of the rivet will be equal to sum of the thickness of the connecting plates plus 1.5 to 1.7 times the diameter of the rivet.

If, l = length of the shank of the rivet
d = diameter of rivet
t = thickness of each of the connecting plates
then, l = Σt + (1.5 to 1.7)d

FORMS AND PROPORTIONS OF RIVET HEADS

Various types of rivet heads for the use in general engineering work and boiler work as recommended by the Bureau of Indian Standards. The different proportions of these rivet heads are given in terms of the nominal diameter d of the rivet. The rivet head to be used for general purposes for diameter below 12 mm are specified in the Indian Standard code IS:2155-1962 and for diameters between 12 and 48 mm are specified in the Indian
Standard code IS:1929-1961. The rivet heads to be used for boiler work are specified in the Indian Standard code IS: 1928-1961. The rivet heads to be used for ship building are specified in the Indian Standard code IS: 4732-1968.

1. Rivet heads for general purposes (below 12 mm diameter) as shown in Fig. according to IS : 2155 – 1982 (Reaffirmed 1996).