One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly in middle of nut and then slot reduced by tightening screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin splitted and bent in reverse direction at the other end
B. A slot is cut partly in middle of nut and then slot reduced by tightening screw
Metric
Buttress
Square
NPT (national pipe threads)
Tearing strength of plate (Pt)
Shearing strength of rivet (Ps)
Crushing strength of rivet (Pc)
Least value of Pt Ps and Pc
Low
High
Moderate
None of these
Bondability
Embeddability
Comformability
Fatigue strength
Pulley is made the weakest
Key is made the weakest
Key is made the strongest
All the three are designed for equal strength
3 mm
5 mm
10 mm
20 mm
Joint may not open up
Bolts are weakest elements
The resultant load on the bolt would not be affected by the external cyclic load
Bolts will not loosen during service
One small nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly in middle of nut and then slot reduced by tightening a screw
Hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is stewed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin splitted and bent in reverse direction at other end
A pair of tongs
Hand wheel of a punching press
Lever of a loaded safety valve
Handle of a hand pump
0.5 to 1
1 to 2
3 to 5
5 to 10
For conveying steam
In water and sewage systems
In pressure lubrication systems on prime movers
All of the above
There is a thick film of lubricant between the journal and the bearing
There is a thin film of lubricant between the journal and the bearing
The lubricant is forced between the journal and the bearing, by external pressure
There is no lubricant between the journal and the bearing
2000 N-m
2050 N-m
2100 N-m
2136 N-m
More than 50 %
Less than 50 %
Equal to 50 %
None of these
Tensile stress
Bending stress
Bearing stress
Shear stress
Half
Same
Double
None of the above
Determining brittleness
Protecting metal against corrosion
Protecting metal against wear and tear
Experimental stress analysis
Pitch circle diameter × cosφ
Addendum circle diameter × cosφ
Clearance circle diameter × cosφ
Pitch circle diameter × sinφ
The pitch of the thread is 24 mm and depth is 2 mm
Cross-sectional area of the threads is 24 mm²
The nominal diameter of bolt is 24 mm and pitch is 2 mm
The effective diameter of bolt is 24 mm and there are 2 threads per cm
Right hand threads on bout ends
Left hand threads on both ends
Left hand threads on one end and right hand threads on other end
No threads
10 to 20 %
20 to 30 %
30 to 40 %
40 to 50 %
Regain its original shape after deformation when the external forces are removed
Draw into wires by the application of a tensile force
Resist fracture due to high impact loads
Retain deformation produced under load permanently
F + P
F P
P
F
Surface
Just below the surface
Within the core
None of the above
Directly proportional to (shaft diameter)²
Inversely proportional to (shaft diameter)²
Directly proportional to (shaft diameter)⁴
Inversely proportional to (shaft diameter)⁴
1/2
1/3
1/4
2/3
Tightening it properly
Increasing shank diameter
Grinding the shank
Making shank diameter equal to core diameter of thread.
Varies linearly
Is uniform throughout
Varies exponentially, being more near the torque-input end
Varies exponentially, being less near the torque-input end
Bolts
Keys
Cotters
Rivets
0.5 times
Equal to
2 times
Double