Design of Riveted Joints Fastening of Riveted Joints

Machine Design (15ME53T), CO-2, Design of Fasteners, Session-7 2020-21

Dept. of Mech. Engg. GPT Kalgi 1

Design of Riveted Joints

Fastening of Riveted Joints • Riveting is a permanent fastening method.

• In modern manufacturing practices welding has replaced riveting to a considerable

extent; it still has its own significance and use in several types of works.

• Riveting is largely used for connecting the parts of boiler, pressure vessels, rail

wagons, coaches, furnace bodies, bridges, etc.

• In this types of joints, rivets are permanent fastener and the plates joined together

by riveting can be separated only either by chipping off the rivet heads or due to

failure of joint.

• A rivet consist of short cylindrical bar known as shank and head at one end of it

Refer fig.

• The main function of rivet is to form a joint that has strength and tightness. It is

necessary to prevent the joint failure and leakages.

Methods of Riveting

Riveting Functions

1. To make a connection that has strength-to prevent failure of loint

2. To make a connection that has tightness-to contribute to strength and prevent leakages in a boiler

or ship hull.

Fig shows the methods of riveting. Two plates are joined with the help of a Rivet.

The rivet is inserted in holes of the plates being joined.

The head of the rivet is held against the backup bar.



The protruded end of shank is upset by manual hammer blows or machine riveting .Refer fig .

This causes the shank to form closing head known as a point.

The rivet used may be hot or cold. In hot riveting the shank is heated to about 1000 oc and in cold

riveting there is no such heating.

The hot riveting is used to make leak proof joints whereas cold riveting is used for structural joints.

Standard sizes of a rivet are12,14,16,18,20,22,24,27,30,33,36,39,42,48, mm. etc.

Rivet materials Rivets used in various engineering applications are made of following materials : usually they are

ytough & ductile

1) Mild steels :

It is most commonly used rivet materials.

There are two varieties of steel rivet bars as hot rolled steel bar Rivet bar and high tensile steel

rivet bar .

2) Stainless steel:

These rivets are used in corrosive atmosphere.

3) Cooper , bronze and aluminum alloys :

These rivets are used for connecting non- ferrous metals soft Materials.

4) Duralumin :

These rivets are used in structural joints of aluminium alloys.

Note : when the rivet material and the part material have different electrochemical Potentials ,they

form galvanic pairs and accelerate the corrosion process. Hence, Most of times the rivets are

made of same material as the parts being joined



Applications of Riveting

1.Connecting the parts of boiler,& pressure vessels

2. Pressure vessels,

3. Rail wagons, coaches,

4. Furnace bodies,

5. Bridges,

6. Aeroplanes

7. Hulls of Ships etc.

Types of riveted joints

Following are the various types of riveted joints used for joining plates :

Types of rivet joints Riveted joints are mainly of two types

1. Lap joints

2. Butt joints

3. Lozenge joint

Lap joints

• The plates that are to be joined are brought face to face such that an overlap exists,

as shown in figure.

• In lap joint, one plate overlaps the other and both plates are riveted.

• Rivets are inserted on the overlapping portion.

• Single or multiple rows of rivets are used to give strength to the joint.

• Depending upon the number of rows the riveted joints may be classified as single

riveted lap joint, double or triple riveted lap joint etc.

• When multiple joints are used, the arrangement of rivets between two neighboring

rows may be of two kinds.

• In chain riveting the adjacent rows have rivets in the same transverse line.

• In zig-zag riveting, on the other hand, the adjacent rows of rivets are staggered.

1) Lap joint 2) butt joint 3) lozenge joint



Butt Joints

• In this type of joint, the plates are brought to each other without forming any

overlap.

• Two main plates to be joined together are kept in alignment butting (i.e. touching)

each other and a cover plate or strap is placed on either on one side or on both

sides of the main plates.

• Riveted joints are formed between each of the plates and one or two cover plates.

Depending upon the number of cover plates the butt joints may be single strap or

double strap butt joints. A single strap butt joint is shown in figure. Like lap

joints, the arrangement of the rivets may be of various kinds, namely, single row,

double or triple chain or zigzag.

A few types of joints are shown in figure.



Important terms used in riveted joints: Few parameters, which are required to specify arrangement of rivets in a riveted

joint are as follows:

1. Pitch. It is the distance from the centre of one rivet to the centre of the next rivet

measured parallel to the seam as shown in Fig. It is usually denoted by p.

2. Back pitch. It is the perpendicular distance between the centre lines of the

successive rows as shown in Fig. It is usually denoted by pb.

3. Diagonal pitch. It is the distance between the centres of the rivets in adjacent

rows of zig-zag riveted joint as shown in Fig. It is usually denoted by pd.

4. Margin or marginal pitch. It is the distance between the centre of rivet hole to

the nearest edge of the plate as shown in Fig. It is usually denoted by m.



Multiple choice questions Test

1. A rivet is specified by

(a) shank diameter (b) length of rivet (c) type of head (d) length of tail

2. The diameter of the rivet hole is usually ........ the nominal diameter of the

rivet.

(a) equal to (b) less than (c) more than

3. A line joining the centres of rivets and parallel to the edge of the plate is

known as

(a) back pitch (b) marginal pitch (c) gauge line (d) pitch line

4. The centre to centre distance between two consecutive rivets in a row, is called

(a) margin (b) pitch (c) back pitch (d) diagonal pitch

5. The objective of caulking in a riveted joint is to make the joint

(a) free from corrosion (b) stronger in tension (c) free from stresses (d) leak-proof

6. A joint is said to be double-riveted, triple riveted etc. accordingly to the

number of sheets used.

a) True

b) False

7. In a lap joint, if the plates are connected to each other when the joint is made

with only one row of rivets then it is called double-riveted lap joint.

a) True

b) False

8. Which of the following isn’t a main part of rivet?

a) Head b) Shank c) Point d) Thread

9. Riveting is not recommended for aluminium alloys.

a) True

b) False

10. Which of the following is a permanent fastening?

(A) Bolts

(B) Keys

(C) Cotters

(D) None of these



Answers to MCQ

1. (a) 2. (c) 3. (a) 4. (b) 5. (d)

6. (b) 7. (b) 8. (b) 9. (b) 10. (d)

Design of Riveted Joints Fastening of Riveted Joints

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