During hot working of metals
Poor surface finish is produced
Scale is formed on the metal surface
Close tolerances cannot be maintained
All of these
Correct Answer :
D. All of these
Related Questions
A casting defect which occurs due to improper venting of sand is known as
Cold shuts
Blow holes
Shift
Swell
The property of sand due to which it evolves a great amount of steam and other gases is called
Collapsibility
Permeability
Cohesiveness
Adhesiveness
In spot welding, the spacing between two spot weld should not be less than
d
1.5 d
3 d
6 d
In order to deliver molten metal from pouring basin to gate, a ________ is used.
Riser
Sprue
Core
None of these
A progressive limit gauge has
'Go' and 'Not go' member on the same side of the gauge
Separate 'Go' and 'Not go' members
'Go' member at one end and 'Not go' member at the other end
None of the above
Which of the following methods can be used for manufacturing 2 metre long seamless metallic tubes?
Drawing
Extrusion
Rolling
Extrusion and rolling
Rotary swaging
Is extensively used for making bolts and rivets
Is used for reducing the diameters of round bars and a tube by rotating dies which open and close rapidly on the work
Is used to improve fatigue resistance of the metal by setting up compressive stresses in its surface
Consists of pressing the metal inside a chamber to force it out by high pressure through an orifice which is shaped to provide the desired form of the finished part
The sand used for making cores is
Green sand
Dry sand
Loam sand
Oil sand
The metal is subjected to mechanical working for
Refining grain size
Reducing original block into desired shape
Controlling the direction of flow lines
All of these
Aluminium is the best material for making patterns because it is
Light in weight
Easy to work
Corrosion resistant
All of these
The cross-section of a chisel is usually
Rectangular
Square
Hexagonal
Octagonal
Seam welding is a
Continuous spot welding process
Multi-spot welding process
Arc welding process
Process used for joining round bars
In a _________, both cutting and non-cutting operations are performed at one station of the press in every stroke of the ram.
Simple die
Progressive die
Combination die
Compound die
The operation of cutting of a flat sheet to the desired shape is called
Shearing
Piercing
Punching
Blanking
In average work, the tolerance produced by investment casting method is
±0.05 mm
+0.2 mm
+05 mm
+1 mm
When a pattern is made in three parts, the top part, is known as a
Drag
Cheek
Cope
None of these
In a ________, two or more operations are performed simultaneously at the single stroke of the ram.
Simple die
Progressive die
Combination die
Compound die
Carburising flame is used to weld
Steel, cast iron, copper, aluminium etc
Brass and bronze
Hard surfacing materials such as stellite
All of these
The process extensively used for making bolts and nuts is
Hot piercing
Extrusion
Cold peening
Cold heading
Lancing is the operation of
Cutting a sheet of metal in a straight line along the length
Removal of metal to the desired shape from the edge of a plate
Cutting a sheet of metal through part of its length and then bending the cut portion
Bending a sheet of metal along a curved axis
A basic hole is one whose
Lower deviation is zero
Upper deviation is zero
Lower and upper deviations are zero
None of these
The electrode tip diameter (d) in spot welding should be equal to (where t = Thickness of plate to be welded)
t
1.5 t
3 t
6 t
Riddle is used for
Smoothing and cleaning out depressions in the mould
Cleaning the moulding sand
Moistening the sand around the edge before removing pattern
Reinforcement of sand in the top part of moulding box
The blank diameter used in thread rolling will be
Equal to minor diameter of the thread
Equal to pitch diameter of the thread
A little larger than the minor diameter of the thread
A little larger than the pitch diameter of the thread
For cutting brass, the hacksaw blade should have __________ teeth per 25 mm.
14
24
32
40
The recrystallisation temperature of steel is
400°C
600°C
800°C
None of these
When a pattern is made in three parts, the ________ is known as a drag.
Bottom part
Middle part
Top part
None of these
Galvanising is a
Zinc diffusion process
Process of coating zinc by hot dipping
Process used for making thin phosphate coating on steel
None of the above
A file with 20 teeth in 25 mm is called
Rough file
Bastard file
Second cut file
Smooth file
In die casting, machining allowance is
Small
Large
Very large
Not provided