In metal machining, the work-tool contact zone is a zone where heat is generated due to
Plastic deformation of metal
Burnishing friction
Friction between the moving chip and the tool face
None of the above
Correct Answer :
B. Burnishing friction
Related Questions
The average cutting speed for turning brass with a high speed steel tool is
15 to 19 m/min
25 to 31 m/min
60 to 90 m/min
90 to 120 m/min
The hardness of a grinding wheel is determined by the
Hardness of abrasive grains
Ability of the bond to retain abrasives
Hardness of the bond
Ability of the grinding wheel to penetrate the work piece
What is the name of the device used in arc welding circuits for the purpose of modifying the rate of current change when the weld road is varied rapidly?
Reactor
Kerf
Inductor
Cone
In the relation VTn = C, the value of n for carbide tools is
0.1 to 0.2
0.20 to 0.25
0.25 to 0.40
0.40 to 0.55
Relief angles on high speed steel tools usually vary from
0° to 3°
3° to 10°
10° to 20°
20° to 30°
In oblique cutting system, the cutting edge of the tool
May clear the width of the workpiece
May or may not clear the width of the workpiece
May not clear the width of the workpiece
Should always clear the width of the workpiece
A drill mainly used in drilling brass, copper or softer materials, is
Flat drill
Straight fluted drill
Parallel shank twist drill
Tapered shank twist drill
The rake angle required to machine brass by high speed steel tool is
0°
10°
20°
100°
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
The purpose of jigs and fixtures is to
Increase machining accuracy
Facilitate interchangeability
Decrease expenditure on quality control
All of these
Which of the following statement is wrong about ultrasonic machining?
It is best suited for machining hard and brittle materials
It cuts materials at very slow speeds
It removes large amount of material
It produces good surface finish
The saw milling is an operation of
Producing grooves around the periphery of a cylindrical or conical workpiece
Producing narrow slots or grooves on a workpiece
Reproduction of an outline of a template on a workpiece
Machining several surfaces of a workpiece simultaneously
In oblique cutting system, the maximum chip thickness
Occurs at the middle
May not occur at the middle
Depends upon the material of the tool
Depends upon the geometry of the tool
Which of the following statement is wrong?
The diamond is the hardest tool material and can run at cutting speeds about 50 times that of high speed steel tool.
The ceramic tools can be used at cutting speeds 40 times that of high speed steel tools.
The cemented carbide tools can be used at cutting speeds 10 times that of high speed steel tools.
The ceramic tools can withstand temperature upto 600°C only.
In lapping operation, the amount of metal removed is
0.005 to 0.01 mm
0.01 to 0.1 mm
0.05 to 0.1 mm
0.5 to 1 mm
In a metal arc welding process, a gas metal arc welding with magnetized flux is used and can be done in all the positions i.e. flat position, vertical position or inclined position.
Globular transfer
Spray transfer
GMAW practice
Dip transfer
When the tool moves parallel to the lathe axis, the movement is termed as
Cross feed
Angular feed
Longitudinal feed
Any one of these
The tailstock set over required to turn a taper on the entire length of a workpiece having diameters D and d is
(D - d)/2L
(D - d)/L
(D - d)/2
D - d
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.
What is the method of brazing used to join relatively small assemblies made from materials that either do not oxidize at the brazing temperature or can be protected from oxidation with a flux?
Torch brazing
Dip brazing
Resistance brazing
Furnace brazing
The material which on machining produces chips with built up edge is
Brittle material
Tough material
Hard material
Ductile material
In order to grind soft material
Coarse grained grinding wheel is used
Fine grained grinding wheel is used
Medium grained grinding wheel is used
Any one of these
The tool life in case of a grinding wheel is the time
Between two successive regrinds of the wheel
Taken for the wheel to be balanced
Taken between two successive wheel dressings
Taken for a wear of 1 mm on its diameter
In up milling, the thickness of chip is
Minimum at the beginning of the cut and maximum at the end of the cut
Maximum at the beginning of the cut and minimum at the end of the cut
Uniform throughout the cut
None of these
The operation in which oil is permeated into the pores of a powder metallurgy product is known as
Mixing
Sintering
Impregnation
Infiltration
In drilling softer materials, the cutting speed is _________ as compared to harder materials.
Same
Low
High
None of these
The operation of smoothing and squaring the surface around a hole is known as
Counter-sinking
Counter-boring
Trepanning
Spot facing
The cutting speed of a drill depends upon the
Material of drill
Type of material to be drilled
Quality of surface finish desired
All of these
The cutting speed is minimum while machining _________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
In a single point tool, the angle between the surface of the flank immediately below the point and a line drawn from the point perpendicular to the base, is known as
Side relief angle
End relief angle
Back rake angle
Side rake angle