When the cutting edge of the tool is dull, then during machining
Continuous chips are formed
Discontinuous chips are formed
Continuous chips with built-up edge are formed
No chips are formed
Correct Answer :
C. Continuous chips with built-up edge are formed
Related Questions
The shear velocity is the velocity of
Tool relative to the workpiece
Chip relative to the tool
Tool along the tool face
None of these
In drilling brass, a drill with
Zero helix angle is used
Low helix angle is used
High helix angle is used
Any helix angle can be used
The mechanism of material removal in EDM process is
Melting and Evaporation
Melting and Corrosion
Erosion and Cavitations
Cavitations and Evaporation
In a shaper, the metal is removed during
Forward stroke
Return stroke
Both the forward and return strokes
Neither the forward nor the return stroke
High speed steel cutting tools operate at cutting speeds _________ than carbon steel tools.
2 to 3 times lower
2 to 3 times higher
5 to 8 times higher
8 to 20 times higher
A single point tool has
Rake angle
Cutting angle
Lip angle
All of these
Ceramic cutting tools are
Made by cold pressing of aluminium oxide powder
Available in the form of tips
Brittle and have low bending strength
All of these
Gear lapping is an operation
After heat treatment
Prior to heat treatment
For gear reconditioning
None of these
The carbide tools operating at very low cutting speeds (below 30 m/min)
Reduces tool life
Increases tool life
Have no effect on tool life
Spoils the work piece
In centre less grinders, the maximum angular adjustment of the regulating wheel is
5°
10°
15°
20°
Larger than 15° side cutting edge angle
Increases tool life
Decreases tool life
Produces chipping and decreases tool life
Results in excessive stress concentration and greater heat generation
For machining a cast iron workpiece by a high speed steel tool, the average cutting speed is
10 m/min
15 m/min
22 m/min
30 m/min
The grinding of long, slender shafts or bars is usually done by
In-feed grinding
Through feed grinding
End-feed grinding
Any one of these
A __________ grinding wheel is used to grind soft materials.
Course grained
Medium grained
Fine grained
None of these
In ECM, the material removal is due to
Corrosion
Erosion
Fusion
Ion displacement
Segmental chips are formed during machining
Mild steel
Cast iron
High speed steel
High carbon steel
The actual feed in centerless grinders is given by (where d = Dia. of regulating wheel, n = Revolutions per minute, and α = Angle of inclination of wheel)
πd
πdn
πdn sinα
πdn cosα
It is required to cut screw threads of 2 mm pitch on a lathe. The lead screw has a pitch of 6 mm. If the spindle speed is 60 r.p.m., then the speed of lead screw will be
10 r.p.m.
20 r.p.m.
120 r.p.m.
180 r.p.m.
The operation performed on a shaper is
Machining horizontal surface
Machining vertical surface
Machining angular surface
All of these
In electrochemical machining, the gap between the tool and work is kept as
0.1 mm
0.4 mm
0.35
0.75 mm
Fixtures are used
For holding and guiding the tool in drilling, reaming or tapping operations
For holding the work in milling, grinding, planing or turning operations
To check the accuracy of workpiece
None of the above
When the shear angle is large
Path of shear is short and chip is thin
Path of shear is large and chip is thick
Path of shear is short and chip is thick
Path of shear is large and chip is thin
The process of removing metal by a cutter which is rotated in the same direction of travel of workpiece, is called
Up milling
Down milling
Face milling
End milling
In which of the following machine, the work is usually rotated while the drill is fed into work?
Sensitive drilling machine
Radial drilling machine
Gang drilling machine
Deep hole drilling machine
Threading is an operation of
Smoothing and squaring the surface around a hole
Sizing and finishing a small diameter hole
Producing a hole by removing metal along the circumference of a hollow cutting tool
Cutting helical grooves on the external cylindrical surface
Relief angles on high speed steel tools usually vary from
0° to 3°
3° to 10°
10° to 20°
20° to 30°
Soft materials can not be economically ground due to
High temperature involved
Frequent wheel clogging
Rapid wheel wear
Low work piece stiffness
The cutting speed is maximum while machining __________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
Hot rolling of mild steel is carried out
At recrystallization temperature
Between 100⁰C to 150⁰C
Between recrystallization temperature
Above recrystallization temperature
Which of the following statement is correct as regard to up milling?
It cannot be used on old machines due to backlash between the feed screw of the table and the nut.
The chips are disposed off easily and do not interfere with the cutting.
The surface milled appears to be slightly wavy.
The coolant can be poured directly at the cutting zone where the cutting force is maximum.