An open structure of a grinding wheel is used for
Soft materials
Tough materials
Ductile materials
All of these
Correct Answer :
D. All of these
Related Questions
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.
Crater wear is predominant in
Carbon tool steels
Tungsten carbide tools
High speed steel tools
Ceramic tools
The size of abrasive grain required in a grinding wheel depends upon the
Amount of material to be removed
Hardness of material being ground
Finish desired
All of these
The chuck preferred for quick setting and accurate centering of a job is
Four jaw independent chuck
Collect chuck
Three jaw universal chuck
Magnetic chuck
In drilling aluminium, a drill with
Zero helix angle is used
Low helix angle is used
High helix angle is used
Any helix angle can be used
A dynamometer is a device used for the measurement of
Chip thickness ratio
Forces during metal cutting
Wear of the cutting tool
Deflection of the cutting tool
Calculate the weld per minute, work speed of circular electrode of 220 mm diameter for carrying out seam welding at 4 welds per cm on 1.6 mm thick mild steel tube. Welding cycle consists of 3 cycles on and 2 cycles off Power supply is at 50 Hz.
3000 welds / min, 75 mm / min
600 welds / min, 1500 mm / min
500 welds/ min, 1250 mm/min
22 welds / min, 55 mm / min
If the cutting speed is increased, then the built-up-edge
Becomes longer
May or may not form
Becomes smaller and finally does not form at all
Has nothing to do with speed
Glazing in grinding wheels takes place when the
Wheel is too hard or wheel revolves at a very high speed
Wheel is too soft or wheel revolves at a very slow speed
Wheel is too hard and wheel revolves at very slow speed
Wheel is too soft and wheel revolves at a very high speed
The cutting speed for drilling copper with high speed steel drills varies from
10 to 20 m/min
18 to 30 m/min
24 to 45 m/min
60 to 90 m/min
Discontinuous chips are formed during machining of
Brittle metals
Ductile metals
Hard metals
Soft metals
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
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
An important geometrical quantity in the cutting of metals which can be used as a criterion for machinability of metals is
Cutting speed
Feed rate
Shear angle
Tool geometry
When the tool moves parallel to the lathe axis, the movement is termed as
Cross feed
Angular feed
Longitudinal feed
Any one of these
Volume of a cube of side l and volume of a sphere of radius r are equal. Both the cube and the sphere are solid and of same material. They are being cast. The ratio of the solidification time of the cube to the same of the sphere is
(4π/6)³ × (r/l)⁶
(4π/6) × (r/l)²
(4π/6)² × (r/l)³
(4π/6)² × (r/l)⁴
The cutting speed is minimum while machining _________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
The enlarging of an existing circular hole with a rotating single point tool is called
Boring
Drilling
Reaming
Internal turning
The effect of setting a boring tool above centre height leads to
Increase in the effective rake angle and a decrease in the effective clearance angle
Increase in both effective rake angle and effective clearance angle
Decrease in the effective rake angle and an increase in the effective clearance angle
Decrease in both effective rake angle and effective clearance angle
In an interchangeable assembly, shafts of size 25.000 -0.0100⁺⁰⁰⁴⁰ mm mate with holes of size 25.000 -0.010⁺⁰⁰²⁰ mm. The maximum possible clearance in the assembly will be
10 microns
20 microns
30 microns
60 microns
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
Relief angles on high speed steel tools usually vary from
0° to 3°
3° to 10°
10° to 20°
20° to 30°
In machining metals, surface roughness is due to
Feed marks or ridges left by the cutting tool
Fragment of built-up edge on the machined surface
Cutting tool vibrations
All of these
The hardness of a grinding wheel is specified by
Brinell hardness number
Rockwell hardness number
Vickers pyramid number
Letter of alphabet
Gear finishing operation is called
Shaping
Milling
Hobbing
Burnishing
The cutting fluid mostly used for machining steel is
Water
Soluble oil
Dry
Heavy oils
The vector sum of cutting velocity and chip velocity is __________ shear velocity.
Equal to
Less than
More than
None of these
The factor considered for evaluation of machinability is
Cutting forces and power consumption
Tool life
Type of chips and shear angle
All of these
Buffing wheels are made of
Softer metals
Cotton fabric
Carbon
Graphite
If a particular Fe-C alloy contains less than 0.83% carbon, it is called
High speed steel
Hypo eutectoid steel
Hyper eutectoid steel
Cast iron