1. MACHINE PARTS (FOR DCE / DIT)
Books for reference
Notation: (i) N – engineering drawing ( By N.D.Bhatt) – Latest edition
(ii) M – Machine drawing ( By N.D.Bhatt)
MACHINE PARTS
6. Nuts (N)

2. FASTENERS
Fastners are used to hold together or to assemble separate parts.
Fastners are of two types:
Permanent Fastners
Temporary Fastners
When separate parts are permanently fastened together by welding or riveting, they are called as permanent fastners.
When separate parts are assembled & disassembled as & when needed by threaded fastners, they are called temporary fastners.

3. SCREW THREAD TECHNOLOGY
A ridge of uniform section in the form of helix on the outer or inside surface of a cylinder or a cone is known as screw technology.
The thread formed on the surface of a cylinder is called Straight Thread
The thread formed on the surface of a cone is called Taper Screw thread.

4. SCREW THREAD NOMENCLATURE
PITCH : - The distance, between corresponding points on adjacent thread forms, measured parallel to the axis, is called as pitch.
It is also number of thread forms per unit length of thread.
LEAD : - It is the distance by which threaded parts move axially w.r.t. a fixed mating parts when given one complete revolution.
RIGHT HAND THREAD : - A nut screws on a bolt, when turned clockwise, then the thread is called Right Hand Thread. Generally, the threads are right handed thread.
LEFT HAND THREAD : - A nut screws off a bolt, when turned clockwise, then the thread is called lEFT Hand Thread.

5. NOMENCLATURE OF THREADS
Angle
Flank
Lead
out side diameter
Root / Core dia
Nominal diameter
Root
Pitch
Crest
NOMENCLATURE OF THREADS

6. EXTERNAL THREAD
INTERNAL THREAD

7. TYPES OF THREADS T P
90 d
T= d = 0.5P
SQUARE THREAD

8. TYPES OF THREADS
55° P
d/6 D d
D=0.96P
d=0.64P
WHITWORTH THREAD

9. TYPES OF THREADS p T d
29°
T=0.3707p
d= 0.5p mm
ACME THREAD

10. TYPES OF THREADS
d/8 P D F d
45°
D = P
d = 0.75P
BUTTRESS THREAD

11. TYPES OF THREADS P R D
R=0.25P
D=0.5P
KNUCKLE THREAD

12. HEXAGONAL NUT AND WASHER40 w 52 48 24 20
100 24 3
HEXAGONAL HEADED BOLT
WITH
HEXAGONAL NUT AND WASHER

13. RIVETED JOINTS Types of riveted joints
Rivets are used to fasten permanently two or more plates
or pieces of metal .Joints made with rivets are called
riveted joints.
They are commonly used in ship building and for the
Construction of steel buildings ,bridges ,boilers ,tanks, etc.
Plates joined together by means of a riveted joint cannot be
disconnected without Chipping –off rivet heads from one side
of the joint
Types of riveted joints
Lap joint:- In a lap joint the plates to be connected over lap each other
Butt joint:- In a butt joint edges of the plates to be connected butt against each other and the joint between them is covered by butt –plates

14. Double riveted lap joint Double riveted (zig zag) lap jointPr L
Double riveted (zig zag)
lap joint A Pd P
1.5d Pr t

15. Single riveted butt jointP A A
Single riveted butt joint

16. FOUNDATION BOLTS
These bolts are used for fixing machines to their foundations.
Simple forms of these bolts can quickly forged from mild steel or wrought iron bar .These bolts are suspended in hole and cement grout is then poured to fill up the space around them

17. EYE FOUNDATION BOLT
2.5 D D
15 D D

18. RAG FOUNDATION BOLT 48 72
120

19. LEWIS FOUNDATION BOLT
ø24 24 16 36
105

20. 0.8D
1.5D 2D 2D
0.4D
1.5D
LIFTING EYE-BOLT

21. 2D D D 2D
EYE BOLT

22. TYPES OF NUTS D
0.25D
2.2D
Flanged nut

23. D
0.5D
0.25D
1.5D+3
Cap nut

24. 0.5D D D
Dome nut

25. 1.8D D
0.2D
Capstan nut

26. 0.5D
1.8D
1.5D D
Ring nut
Wing nut

27. PREVENTION OF ROTATION OF BOLTS
(by means of pins, square neck or snug)
T-headed bolt
0.8D D
1.8D
Hook bolt
0.8D D
Counter sunk headed bolt
0.8D D
Cup headed bolt D
0.8D

28. Square headed bolt
Cup headed bolt
Cheese headed bolt

29. LOCKING ARRANGEMENT FOR
NUTS
SPLIT-PIN

30. D
0.6D
LOCK NUT OR CHECK NUT

31. NUT BOLT WITH SPRING WASHER

32. CASTLE NUT WITH A SPLIT PIN

33. SLOTTED NUT WITH A SPLIT PIN

34. COTTER JOINT

35. KNUCKLE JOINT

36. FLANGE COUPLING

37. PROTECTIVE FLANGE COUPLING

38. FOOT STEP BEARING
BUSHED BEARING

39. PLUMMER BLOCK

40. PREVENTING ROTATION OF BRASSES
By making a step rectangular on the one outside and fitting inside a corresponding hole

41. PREVENTING ROTATION OF BRASSES
SNUGS
By snugs at the side

42. PREVENTING ROTATION OF BRASSES
SNUGS
By snugs at the top fitting inside the cap. the oil hole is drilled inside a corresponding hole.

43. PREVENTING ROTATION OF BRASSES
by making the step octagonal on the outside and fitting inside a corresponding hole.