1. FASTENERS AND ANCHORS
CONTREN Series #

2. 1.0.0 Introduction
Industry used a multitude of types of fasteners to assemble and install equipment, parts, and materials.
Industrial Maintenance personnel must be familiar with the different types of fasteners and their applications.

3. 2.0.0 Threaded Fasteners Most commonly used fastener.
Uses threads to hold parts together.
Terminology includes:
Nuts
Bolts
Screws

4. 2.1.0 Thread Standards
Threads are manufactured to industry-established standards for uniformity.
Unified Standard (American Standard)
The most common thread standard.
Establishes thread series and thread classes.

5. 2.1.1 Thread Series Groups threads by pitch (threads per inch).
UNC – Unified National Coarse
General-purpose use
UNF – Unified National Fine
Finer threads for a tighter fit
UNEF – Unified National Extra Fine
For thin-wall tubes, nuts, ferrules, and couplings

6. 2.1.2 Thread Classes
Groups threads by the degree of tolerance permitted.
Class A is for external threads (bolts)
Class B is for internal threads (nuts)

7. 2.1.2 Thread Classes Class 1A – loose fitting bolt threads
Used for quick and easy threading
Used in areas with high contamination
Maximum clearance on bolt threads
Class 2A – bolt threads with nominal clearance
Most commonly used thread class for bolts
Class 3A – tight fitting bolt threads
Used when precision fit is required
Threads must be very clean
Minimum clearance on bolt threads

8. 2.1.2 Thread Classes Class 1B – loose fitting nut threads
Used for quick and easy threading
Used in areas with high contamination
Maximum clearance on nut threads
Class 2B – nut threads with nominal clearance
Most commonly used thread class for nuts
Class 3B – tight fitting nut threads
Used when precision fit is required
Threads must be very clean
Minimum clearance on nut threads

9. 2.1.3 Thread Identification
¾ - 10 UNC – 2A - LH
(1) (2) (3) (4) (5)
Nominal size
Approximate diameter of fastener ( fractional)
TPI - Threads per Inch (Pitch)
Each nominal diameter has a standard number of threads per inch per series
Thread Series Symbol
Indicates the unified standard thread series
(UNC, UNF, UNEF)
Thread Class Symbol
Indicates the closeness of fit between the bolt threads (1A,2A, 3A) and the nut threads (1B, 2B, 3B)
Left Hand Thread Symbol
Used ONLY if threads are left-handed

10. 2.1.4 Thread Design Unified Standard Threads
Standard thread design for most all common bolts and nuts
Used primarily to hold parts together

11. 2.1.4 Thread Design Power Transmission Threads
Used to move machine parts for the purpose of adjusting, setting, or transmitting power.
Not typically used to hold parts together.
The following three thread designs are the most common Power Transmission Threads

12. 2.1.4 Thread Design Buttress Threads
One side of thread is cut square, the other side has a slant
Great strength along thread axis in one direction only
Used extensively to screw thin tubular parts together

13. 2.1.4 Thread Design Square Threads Strongest thread
Threads have parallel sides
Hard to machine

14. 2.1.4 Thread Design Acme Threads
Easier to machine than the square thread
Almost as strong as the square thread

15. 2.1.5 Grade Markings
Markings on the head of the bolt to signify the quality of the bolt.
SAE (Society of Automotive Engineers)
ASTM (American Society for Testing and Materials International)
Established these standards
The greater the number of marks, the higher the quality of the bolt.

16. 2.1.5 Grade Markings No Marks SAE Grade 1 SAE Grade 2 ASTM A307
Low Carbon
74,000 psi
3 Marks
SAE Grade 5
ASTM A449
Medium Carbon
Tempered
120,000 psi
A449
6 Marks
SAE Grade 8
ASTM A354
Medium Carbon
Quenched & Tempered
150,000 psi
5 Marks
SAE Grade 7
Medium Carbon
Quenched & Tempered
133,000 psi

17. 2.2.0 Bolt and Screw Types Made in a variety of shapes
Made from a variety of materials
Identified by the head type

18. 2.2.1 Machine Screws Used for general assembly
Size range from very small to ½” diameter
Slotted
Pozidriv
Phillips
Torx
Hex (Allen)
Clutch
Robertson

19. 2.2.1 Machine Screws Head designations PAN HEAD FILLISTER HEAD
TRUSS HEAD
FLAT HEAD
OVAL HEAD
ROUND HEAD

20. 2.2.2 Machine Bolts
Used for assembly where close tolerances are not required.
Size range from ¼” to 3”.
Normally have a square (4 sides) or hexagonal (6 sides) head.

21. 2.2.3 Cap Screws
Used on high-quality assemblies where a finished appearance is required

22. 2.2.4 Setscrews Made of heat-treated steel
Used to lock pulleys and gears on shafts to prevent slipping
Flat (Half-Dog)
Cone
Cup
Oval
Full (Full-Dog)
Knurled

23. 2.2.5 Stud Bolts Threaded on both ends
Screwed into a tapped hole in the back part with a nut on the other end holding the front part tight against the back part
Thread Rod is a type that is threaded along the full length of the stud

24. 2.3.0 Nuts Different configurations for different applications
Usually, most are hexagonal or square
coupling nut
regular hex nut
regular square nut
flange nut

25. 2.3.1 Jam Nut
Used to lock a standard nut in place on a bolt or stud bolt
Typically, about half the height of a regular nut
jam nut
regular hex nut

26. 2.3.2 Castellated, Slotted, and Self-Locking Nuts
Used in critical applications where the nut cannot be allowed to loosen
bolt cuts threads in
the nylon insert
cotter pin placed through
slot and hole in bolt
nylon locking nut
slotted nut
deformation causes
thread interference
cotter pin placed through
slot and hole in bolt
castle nut
self-locking nut

27. 2.3.3 Acorn Nuts Used when appearance is important
Used when safety is important by covering the sharp threads on the end of the bolt or stud
cap (acorn) nut

28. 2.3.4 Wing Nut Used for rapid tightening and loosening by hand only

29. 2.4.0 Washers Fits under the bolt head or nut
Used to enlarge the area of force onto the work piece
Lock washers also prohibits loosening of the bolt or nut

30. 2.4.1 Lock Washers Designed to keep the bolt or nut from working loose
External
(Greatest Resistance)
Internal
Split-Ring
Internal - External
Countersunk
Ribbed

31. 2.4.2 Flat and Fender Washers
Flat washer spreads the load over a larger area
Fender Washers forms a bridge over a large hole
Cone Washer
-for appearance
Fender Washer
-for oversized holes
Flat Washer
Wedge Washer
-for angled surface
Shoulder Washer
-for insulation
Wave Washer
-for preloading

32. 2.5.0 Installing Threaded Fasteners
Assure proper hole size for the type of bolt
Torque bolt and nut to correct setting
Use safety wire or cotter pin, if required
Most important, use correct grade of bolt

33. 3.0.0 Non-Threaded Fasteners
There are many other fastening devices that are not threaded
Retainers
Pins
Clamps
Rivets
Tie Wraps

34. 3.1.0 Retainer Fasteners Internal and external holding
Non-Groove Fasteners
Groove Fasteners
Internal Self-Locking Ring
Internal Retaining Ring
External Retaining Ring
Spiral Ring
E Ring
External Self-Locking Ring

35. 3.2.0 Keys
A keyway slot is cut in the shaft and the component to be locked to it.
A key is inserted into the keyway
Square Key
Gib Head Key
Pratt & Whitney Key
Woodruff Key
(Semi-Circular)

36. 3.3.0 Pin Fasteners Long, circular fasteners Dowel Pins Taper Pins
Spring Pins
Cotter Pins

37. 3.3.1 Dowel Pins Precise positioning of mating parts
Grooved pins have a higher holding capability due to spring action of the grooves

38. 3.3.2 Taper and Spring Pins
Normally used to lock gears, pulleys, etc onto a shaft
The taper allows for a tight “wedge” fit
Spring (Roll) pins compress into the hole, creating a very tight fit
Taper Pin
Spring Pin

39. 3.3.3 Cotter Pins
Usually inserted through a hole drilled crosswise through the shaft
Used to keep components from falling off the shaft
Cotter Pin
Shaft Lock
Spread ends apart to keep cotter pin from backing out
Hitch Pin
Pull Loop

40. 3.4.0 Blind / Pop Rivets
Ideal fastener for fastening when only one side of the joint can be reached.

41. 3.5.0 Tie Wraps
Self-locking strap (usually nylon) to fasten bundles of cables or wires together

42. 4.0.0 Special Fasteners
Threaded fasteners designed for a specific application.
Eye Bolts
Thread Inserts
Panel and Electrical Mounts

43. 4.1.0 Eye Bolts
Has a loop (eye) on one end for attaching lifting cables or for cable or wire guides
Swivel Eye Bolt
Plain Eye Bolt
Shoulder Eye Bolt

44. 4.2.0 Thread Inserts Provides high strength threads in soft material
Replaces damaged or stripped threads in tapped holes
Heli-Coil
Thread
Inserts
This end goes in first.
Insertion tool grips this prong.
E-Z Lock
Thread
Inserts

45. 4.3.0 Panel and Electrical Mounts
Stamped from sheet metal
Clips to panels for attaching components
J-nut
G-nut
regular nut attached
Cage Nut
Regular nut caged in
a spring clip
U-nut

46. 5.0.0 Mechanical Anchors
Used to attach components to a material that cannot tapped or the back side is unreachable
One-Step Anchors
Bolt Anchors
Screw Anchors
Self-Drilling Anchors

47. 5.1.0 One-Step Anchors
Driven through the component to be anchored and the hole in the substrate at the same time
Wedge Anchors
Stud Bolt Anchors
Sleeve Anchors
One-Piece Anchors
Hammer-Set Anchors
Threaded Rod Anchors

48. 5.1.1 Wedge Anchors
Comes with a wedge on the bottom and a nut and washer on the top
Anchor is driven through the component hole into the substrate hole and tightened with the nut

49. 5.1.2 Stud Bolt Anchors Depth of hole is critical
Threaded wedge is driven down onto the taper to lock it into place

50. 5.1.3 Sleeve Anchors
Comes with a wedge along the length of the anchor and a nut and washer on the top
Anchor is driven through the component hole into the substrate hole and tightened with the nut

51. 5.1.4 One-Piece (Split) Anchors
Drive in with no further tightening
Flex in the split locks the anchor in place

52. 5.1.5 Hammer-Set Anchors
Pushed into a hole, then nail is driven in to lock the anchor in place
Comes with or without a final tightening nut

53. 5.1.6 Threaded Rod Anchors Pushed into a hole
Threading a thread rod expands the housing to lock the anchor in place

54. 5.2.0 Bolt Anchors Installed flush with the surface of the substrate
The component is then anchored with machine bolts
Drop-In Anchors
Single Expansion Anchors
Double Expansion Anchors
Caulk-In Anchors

55. 5.2.1 Drop-In Anchors
Works much like a wedge anchor

56. 5.2.2 Single- and Double-Expansion Anchors
Works much like a sleeve anchor
Double expansion anchors are the best choice with the strength of the substrate is questionable
Double
Single

57. 5.2.3 Lead (Caulk-In) Anchors
Must be driven down with the setting tool to lock the anchor in place

58. 5.3.0 Screw Anchors
Threaded directly into the substrate

59. 5.4.0 Self-Drilling Anchors
Drills its own hole and locks itself in place
Dywidag

60. 5.5.0 Guidelines For Drilling Anchor Holes
Check specifications for proper hole diameter and depth
Check condition of hammer drill and work area
Observe all safety precautions

61. 6.0.0 Epoxy Anchoring Hole is drilled to accept a j-bolt
J-bolt is secured in place by a wood or metal frame
Epoxy is poured into the hole, anchoring the j-bolt