1. Metalwork
Threaded Fasteners

2. Threaded Fasteners
Hello

3. Threaded Fasteners Materials
Threaded fasteners are suitable to be used on all kinds of materials, examples of which are:
Metal
Wood
Plastic

4. The most commonly used materials from which they are made are:
Threaded Fasteners
Threaded fasteners are available in several different materials depending on the purpose for which they will be used.
The most commonly used materials from which they are made are:

5. Threaded Fasteners Low Carbon Steel Medium Carbon Steel
Stainless Steel
Mild Steel
Alloy Steel

6. Threaded Fasteners
Threaded fasteners can also be galvanised for added corrosion resistance for use out side and in costal areas.

7. Threaded Fasteners
Hello

8. Threaded Fasteners Description
Threaded fasteners are mainly used where the parts to be joined may need to be dismantled.

9. Threaded Fasteners The main groups of threaded fasteners include:
Screws
Bolts
Studs
Nuts

10. Threaded Fasteners
By using these, joined parts can be easily separated again when required.

11. Threaded Fasteners Screws Screws serve several purposes:
Joining parts together
Preventing relative movements between parts
Adjustment purposes

12. Threaded Fasteners
Threaded Fasteners

13. Threaded Fasteners Screws
When used for joining 2 parts the screw passes through a clearance hole in one part and is screwed into a tapped hole in the other part. Therefore a nut is not required as one of the parts is essentially acting as the nut.

14. Threaded Fasteners
Screws

15. Threaded Fasteners Screws
There are many different types of screw available:
Set Screw
Grub Screw
Thumb Screw
Self Tapping Screw

16. Threaded Fasteners Set Screws
These are threaded for their full length and are available with various shapes of head.

17. Threaded Fasteners
Set Screw

18. These are used to prevent relative movement between parts.
Threaded Fasteners
Grub Screws
These are used to prevent relative movement between parts.
They can be screwed below the surface therefore when they are used on a revolving shaft there is no fear of them hitting anything.

19. Threaded Fasteners
Grub Screws

20. Threaded Fasteners
Grub Screws

21. Threaded Fasteners Thumb Screws
These screws are tightened and loosened by hand. They are commonly used for locking tools at particular settings.

22. Threaded Fasteners
Thumb Screws

23. Threaded Fasteners
Thumb Screws

24. These are used for sheet metal.
Threaded Fasteners
Self Tapping Screws
These are used for sheet metal.

25. Threaded Fasteners
Self Tapping Screws

26. Threaded Fasteners
Self Tapping Screws

27. Threaded Fasteners Bolts
Bolts are most often used to join parts together with the aid of nuts. Bolts are usually threaded for only a part of their length.

28. Threaded Fasteners
Bolts

29. Threaded Fasteners
Bolts

30. A nut is then screwed onto the bolt and tightened.
Threaded Fasteners
Bolts
When a bolt is used to join 2 or more parts the holes are drilled just large enough for the bolt to slide through them.
A nut is then screwed onto the bolt and tightened.

31. Threaded Fasteners
Bolts

32. Threaded Fasteners Bolts
Bolts have to be able to resist 2 main forces:
Shear
Tension

33. Threaded Fasteners Shear
If the parts being joined have a tendency to slide over each other, the bolt will have to be strong enough to resist shear.

34. Threaded Fasteners
Shear

35. Threaded Fasteners Tension
If the parts have a tendency to pull apart the bolt will have to resist tension. The bolt must also resist tension when the nut is tightened onto it.

36. Threaded Fasteners
Tension

37. Threaded Fasteners Bolts
Bolts are available with various shapes of head such as hexagonal, square and round.

38. Threaded Fasteners Bolts
Bolts are specified by their diameter, type of thread, length, material, finish and shape of head.
E.G.: M10 x 50mm long, Mild Steel, Sherardised and Hexagonal Head.

39. Threaded Fasteners Studs
Studs are threaded at both ends. One end is passed through a clearance hole in one part and screwed into a tapped hole in the main component a nut is screwed onto the end to tighten the parts together.

40. Threaded Fasteners
Studs

41. Threaded Fasteners
Studs

42. They are usually hexagonal or square in shape.
Threaded Fasteners
Nuts
Nuts are made with an internal screw thread to match the thread on a screw, bolt or stud.
They are usually hexagonal or square in shape.

43. Threaded Fasteners
Nuts

44. Threaded Fasteners Nuts
Wing nuts are tightened and loosened by hand so therefore they are only suitable where the degree of tightness achieved is not of vital importance e.g. tensioning hacksaw blades.

45. Threaded Fasteners
Wing Nuts

46. Threaded Fasteners Nuts
Special locking nuts are sometimes used to prevent loosing by vibration. They include:
A thin nut used with a plain nut
A castle or slotted nut used with a split pin
A nut with a nylon or fibre insert

47. Threaded Fasteners
Locking Nuts

48. Threaded Fasteners
Locking Nuts

49. Threaded Fasteners
Locking Nuts

50. Threaded Fasteners
Locking Nuts

51. Threaded Fasteners
Locking Nuts

52. Threaded Fasteners
Locking Nuts

53. Plain washers are commonly used under nuts, bolts and screws.
Threaded Fasteners
Washers
Plain washers are commonly used under nuts, bolts and screws.

54. Threaded Fasteners
Plain Washers

55. Threaded Fasteners
Plain Washer

56. Threaded Fasteners Washers There are 2 reasons for their use:
To prevent the corners of the nut, bolt or screw from scratching the surface of the component.
To distribute the load exerted by the nut, bolt or screw over a larger area.

57. Threaded Fasteners Washers
Washers are also used as locking devices, examples of these are:
Spring washers
Toothed washers
Tab washers

58. Threaded Fasteners
Spring Washer

59. Threaded Fasteners
Spring Washer

60. Threaded Fasteners
Toothed Washer

61. Threaded Fasteners
Toothed Washer

62. Threaded Fasteners
Tab Washer

63. Threaded Fasteners
Tab Washer

64. Threaded Fasteners
Tab Washer