Cold working
Shot peening
Grinding and lapping surface
Hot working
The distance from a point on one thread to the corresponding point on the next thread is called pitch
The distance which a screw thread advances axially in one rotation of the nut is called lead
In single start threads, lead is equal to pitch
All of the above
Plastic materials
Brittle materials
Non-ferrous materials
Ductile materials
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
1.06
1.12
1.26
1.58
Does not change
Increases
Decreases
None of the Above
Screw jack
Aeroplane engines
Crane
Steering mechanism
Is just sufficient to hold parts together
Approaches yield point
Is 50% of yield point
Is about yield point divided by safety factor
d/2
d/3
3d/4
d/4
2000 N-m
2050 N-m
2100 N-m
2136 N-m
Friction angle is less than helix angle
Friction angle is more than helix angle
Friction angle is equal to helix angle
Efficiency of screw is 100%
Always in single shear
Always in double shear
Either in single shear or double shear
Any one of these
W/2
2W/3
W/9
8W/9
The tension in tight side is twice the centrifugal tension
The tension in slack side is equal to the centrifugal tension
The tension in tight side is thrice the centrifugal tension
None of the above
At bottom
At sides only
Both at bottom and sides
Could touch anywhere
8
6
4
10
Diameter of both the shafts is same
Angle of twist of both the shafts is same
Material of both the shafts is same
Twisting moment of both the shafts is same
√2P/s.l
P/2.s.l
P/√2.s.l
2P/s.l
Increasing velocity ratio
For applying tension
Changing the direction of motion of belt
All of these
Tolerance grade for the hole is 6 and for the shaft is 5
Tolerance grade for the shaft is 6 and for the hole is 5
Tolerance grade for the shaft is 4 to 8 and for the hole is 3 to 7
Tolerance grade for the hole is 4 to 8 and for the shaft is 3 to 7
Initial tension
External load applied
Sum of the initial tension and external load applied
Initial tension or external load, whichever is greater
6 m
5 m
7 m
All of these
Woodruff key
Feather key
Flat saddle key
Gib head key
Increasing its shank diameter
Increasing its length
Decreasing its shank diameter
Decreasing its length
Torque in each shaft is the same
Shear stress in each shaft is the same
Angle of twist of each shaft is the same
Torsional stiffness of each shaft is the same
Module
Tooth profile
Both module and pitch line velocity
Pitch line velocity
10 m/s
12.5 m/s
15 m/s
20 m/s
Square threads
Multiple threads
Acme threads
Buttress threads
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
Equal to
Less than
Greater than
None of these