1. RIVETS
&
RIVETED JOINTS

2. UNIT III

3. RIVETS & RIVETED JOINTS
Material for rivets
Essential qualities of Rivet
Methods of Riveting
Purpose of Riveting
Classification of Rivets or Rivet heads
Classification of Riveted joint
Terminology of Riveted joint
Caulking and Fullering operations
Types of Failure and Strength Equations
Riveted Joints for Boiler Shell

4. RIVET
Rivets are short cylindrical pieces of ductile metal having a head, shank and tail
Used to join two or more pieces of sheet metals permanently, plates to rolled sections, rolled section to each other etc…
Rivets are used for joining of sheets and plates in bridges, boilers, storage tanks, pressure vessels and ships etc…

5. MATERIAL FOR RIVETS
Rivets made of mild steel are used in most of the applications
Rivets used in corrosive atmosphere are made of stainless steel
Rivets used for connecting non ferrous metals and soft materials are made of copper, brass, bronze and aluminium alloys
Duralumin rivets are used for structural joints made of aluminium alloy section

6. PROPERTIES OF THE RIVETS
Rivet should be sound, free from cracks, flaws, burrs, seams, pits and other defects
Rivet head should be concentric with axis of the shank
Rivet end should be square with respect to the axis

7. RIVETING
The process of joining two or more plates by means of rivets is called riveting

8. METHODS OF RIVETING
During riveting, rivet head is formed from the tail of the rivet when it is placed in the rivet holes drilled in the plates to be fastened
Forming of head may be either by hand tools or by machines
In machine riveting, force is applied by means of hydraulic or pneumatic pressure

9. METHODS OF RIVETING METHODS OF RIVETING HAND RIVETING MACHINE RIVETING
ON THE BASIS OF TEMPERATURE OF SHANK
HOT RIVETING
COLD RIVETING

10. PURPOSE OF RIVETING
For fluid tightness in case of Boilers, pressure vessels and ships
For strength and rigidity in bridges, trusses, cranes and machinery
For strength, rigidity, durability and leakproofness in shiphull

11. TYPES OF RIVETS Following types of rivets are used for different work
Structural rivets (12 to 45mm dia.):
Boiler rivets (12 to 50mm dia.)
Small rivets (2 to 10mm dia.)
(1) Structural rivets (12 to 45mm dia.): Used for structural work
Round countersunk Countersunk
Head Head
Snap Head
Pan Head
Pan Head with Tapered neck
1111

12. TYPES OF RIVETS
(2) Boiler rivets (12 to 50mm dia.): Used for boiler works
Snap Head
Pan Head
Ellipsoidal
Pan head 1
Conical Head

13. TYPES OF RIVETS
(2) Small rivets (2 to 10mm dia.): Used for general purposes and are of steel brass or aluminium
Mushroom Head
Countersunk Head
Flat Head
1.75d
0.75d
Round Head

14. CLASSIFICATION OF RIVETED JOINTS
Depending upon the manner of placing the plates, riveted joints are classified in to two types
Lap joint and
Butt joint
Lap joint
Butt joint

15. CLASSIFICATION OF RIVETED JOINTS
Depending upon no. of rows of rivets in a joint, riveted joints are divided into two types
Single riveted joint and
Multiple riveted joint
Double riveted
Triple riveted
Quadruple riveted etc…

16. CLASSIFICATION OF RIVETED JOINTS
SINGLE RIVETED LAP JOINT

17. CLASSIFICATION OF RIVETED JOINTS
DOUBLE RIVETED LAP JOINT

18. CLASSIFICATION OF RIVETED JOINTS
SINGLE RIVETED SINGLE STRAP BUTT JOINT

19. CLASSIFICATION OF RIVETED JOINTS
SINGLE RIVETED DOUBLE STRAP BUTT JOINT 29

20. CLASSIFICATION OF RIVETED JOINTS
DOUBLE RIVETED DOUBLE STRAP BUTT JOINT

21. CLASSIFICATION OF RIVETED JOINTS
Depending upon arrangement of rivets in adjacent rows, riveted joints are classified as;
Chain riveted joint and
Zig-zag riveted joint

22. CLASSIFICATION OF RIVETED JOINTS
CHAIN RIVETED JOINT

23. CHAIN RIVETED JOINT

24. ZIG-ZAG RIVETED JOINT

25. ZIG-ZAG RIVETED JOINT

26. LOZENGE RIVETED JOINT

27. CLASSIFICATION OF RIVETED JOINTS
Riveted joints may also be classified as;
Structural joints and
Pressure vessel joints
Angle Joint

28. CLASSIFICATION OF RIVETED JOINTS
Column and Beam Joint

29. CLASSIFICATION OF RIVETED JOINTS
Built up girder

30. TERMINOLOGY OF RIVETED JOINTS
Rivet diameter is represented by ‘d’ and plate
thickness is represented by ‘t’

31. TERMINOLOGY OF RIVETED JOINTS
The thickness of plate (t)
The diameter of the shank (or rivet) (d)
Using Unwin’s formula
d6 t
Standard diameters of rivets as per B.I.S. are shown in the table

32. TERMINOLOGY OF RIVETED JOINTS
LENGTH OF THE SHANK

33. Gauge. line:. It. is. a. line. through. the. centers. of
Gauge line: It is a line through the centers of a row of rivets and parallel to the edge of the plate

34. Pitch or longitudinal pitch : (p)
It is a the distance from the centre of the rivet to the centre of the next rivet in the same row measured on the gauge line

35. Transverse pitch or back pitch or row pitch (pt)
It is a the distance between adjacent gauge lines in the same plate.

36. Diagonal pitch: (pd)
It is a the distance between the centres of adjacent rivets on adjacent gauge lines in the same plate.

37. Margin or Marginal pitch: (m)
It is the distance from the edge of the plate to the entre of the nearest rivet hole.

38. Proportions as per B.I.S.

39. CAULKING AND FULLERING OPERATIONS
To obtain leak proof joints, the edges of the plates to be joined and the rivet heads are forced to gether by caulking and fullering operations
CAULKING
Caulking plate
The outer edges of the plates are bevelled
These bevelled edges of the plates are caulked
Caulking is an operation in which the outer bevelled edges
of the plates are hammered and driven-in by a caulking tool
The caulking tool is in the form of a blunt edged chisel

40. CAULKING AND FULLERING OPERATIONS
Similar to caulking, fullering is also used to produce air tight joints.
Unlike the caulking tool, the width of the fullering tool is equal to the width of the bevelled edges of the plates

41. TYPES OF FAILURE IN RIVETED JOINT
1 Shear failure of the rivet
2 Tensile failure of the plate between two consecutive rivets
3 Crushing failure of the plate
4 Tearing of the plate in the margin area

42. SHEAR FAILURE OF THE RIVETS

43. TENSILE FAILURE OF THE PLATE BETWEEN TWO CONSECUTIVE RIVETS

44. CRUSHING FAILURE OF THE PLATE OR RIVETS

45. TEARING OF THE PLATE IN THE MARGIN AREA

46. DESIGN OF BOILER JOINTS
TYPES OF BOILER JOINTS
LONGITUDINAL BUTT JOINT
2. CIRCUMFERENTIAL LAP JOINT

47. DESIGN OF BOILER JOINTS

48. DESIGN OF LONGITUDINAL BUTT JOINT FOR BOILER

49. DESIGN OF LONGITUDINAL BUTT JOINT FOR BOILER

50. DESIGN OF LONGITUDINAL BUTT JOINT FOR BOILER

51. DESIGN OF LONGITUDINAL BUTT JOINT FOR BOILER
STEP 4 TRANSVERSE PITCH
CASE I:
CASE 2:
CASE 3:

52. DESIGN OF LONGITUDINAL BUTT JOINT FOR BOILER

53. DESIGN OF LONGITUDINAL BUTT JOINT FOR BOILER

54. DESIGN OF CIRCUMFERENTIAL LAP JOINT FOR BOILER

55. DESIGN OF CIRCUMFERENTIAL LAP JOINT FOR BOILER

56. DESIGN OF CIRCUMFERENTIAL LAP JOINT FOR BOILER

57. DESIGN OF CIRCUMFERENTIAL LAP JOINT FOR BOILER

58. DESIGN OF CIRCUMFERENTIAL LAP JOINT FOR BOILER

59. DESIGN OF CIRCUMFERENTIAL LAP JOINT FOR BOILER
STEP 6: DISTANCE BETWEEN ROWS OF RIVETS

60. DESIGN OF CIRCUMFERENTIAL LAP JOINT FOR BOILER

61. ECCENTRICALLY LOADED RIVETED JOINT