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Types of Rivets - ITI Engineering Drawing Theory

Hello Friends in this article you learn about Types of rivets and riveted joints in iti engineering drawing theory, how to draw rivet methods and advantages and disadvantages and read this article. 



ITI Exam

1 Snap head rivet 

(Fig 1) Draw a snap head rivet suitable for joining plates of 25 mm thick.


Diameter of rivet = 6 x 25 = 6 x 5 = 30 mm

• Draw a thin horizontal line.

• Draw vertical centre lines.

• Mark diameter of rivet shank and head.

 • Form the rivet head as per proportions.

• Draw the shank with short break.

• Draw firm lines of the edges of the rivet.

• Show the dimensions in terms of dia of shank. (Fig 1)

 

2 Pan head rivet 

Draw a pan head rivet of shank diameter 30 mm. (Fig 2)


• Follow the procedure of snap head rivet.

 

3 Conical head rivet

Draw a conical head rivet of shows diameter 25 mm. (Fig3)


• Draw a horizontal thin line.

• Draw a vertical centre line.

 • Mark the diameter of rivet head and shank as per proportion.

• Set off 0.8d on the centre line as shown in Fig 3 from the horizontal line.

• 0.25d as radius, draw an arc as shown in Fig 3.

• 1.5d as radius, draw another arc, tangential to the previous arc of radius 0.25d.

• Draw the firm lines of the edges of the rivet.

• Show the dimensions in terms of diameter of shank.

 

4 Countersunk head rivet

 Draw a countersunk head rivet of shank diameter 25 mm.


• Draw a horizontal line.

• Draw a centre line.

• Follow the procedure of earlier exercises and complete the rivet head.


Types of rivets:

• Boiler rivets

• Hot forged rivets for hot closing

• Cold forged solid steel rivets for hot closing

• Non-ferrous rivets

• Cold forged rivets for cold closing

• Bi-furcated rivets for general purposes

• Solid drilled tubular and semi-tubular rivets.

 

Rivets are also broadly classified as:

• Structural rivets

• Boiler rivets

• Small rivets for general work

• Rivets for ship building

• Aircraft rivets.

 

Rivets are manufactured either by cold heading or hot forging. Cold headed rivets are adequately heat-treated so that the stresses set up in the cold heading process are eliminated. If they are hot forged, the finished rivets are cooled gradually. The rivets should be concentric with the shank. They shall be free from imperfection and heavy scales. The ends of the rivets shall be clearly sheared and free from rags or burrs.

They are available in different lengths and selected according to the requirements (IS:1928 for boiler rivets, dia 12 to 48mm).

Boiler rivets of different types of heads as per IS:1928-1961 are shown in Fig 2. They are

• Snap head

• Ellipsoidal head

• Pan head type I & II

• Pan head with taper neck

• Conical head

• Countersunk head

• Rounded countersunk head

• Flat head

• Steeple head

Boiler rivets are used in boiler shells, mountings gussets stays etc. They have generally tapered necks at 60° chamfer for preventing the leakages of steam. Table 1 shows the preferred length and diameter combination for boiler rivets.

 

Structural/General purpose rivets IS:1929, IS:2155:

Structural rivets are used in structures like girders of bridges, trusses of roof etc.

Their shank dia (IS:1929) varies from 12 mm to 36 mm. The proportions shown are for rivets of diameter from 12 mm to 36 mm. The above rivets are used even for general work.

The dimensions are from 12 mm to 50 mm. Structural rivet and boiler rivets are made of low carbon steel and wrought iron. (Fig 3)

Small rivets are used for general work, may be made of "non-ferrous metals" viz copper, brass or aluminium. Diameters are 1.6, 2, 2.5, 3, 4, 5, 6, 8 and 10 mm of varying lengths in steps of 2 mm upto 24 mm and then in steps of 3 mm. IS:2907.

Rivets are designated by its shape, dia, length, IS. No and materials.


ITI ED Exam - ITI Engineering Drawing 

Read Also :- ITI Engineering Drawing Paper


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