Misrun is a casting defect which occurs due to
Very high pouring temperature of the metal
Insufficient fluidity of the molten metal
Absorption of gases by the liquid metal
Improper alignment of the mould flasks
Correct Answer :
B. Insufficient fluidity of the molten metal
Related Questions
The method of centre less grinding used to produce taper is
In-feed grinding
Through feed grinding
End feed grinding
Any one of these
The structure of a grinding wheel depends upon
Hardness of the material being ground
Nature of the grinding operation
Finish required
All of these
Hard and tough materials like cast iron should be turned at
Slow speed
High speed
Any speed
Certain specific speed
In a CNC program block, N002 GO2 G91 X40 Z40......, GO2 and G91 refer to
Circular interpolation in counter clockwise direction and incremental dimension
Circular interpolation in counter clockwise direction and absolute dimension
Circular interpolation in clockwise direction and incremental dimension
Circular interpolation in clockwise direction and absolute dimension
The floating position of the holding fixture in a rotary transfer device is used to
Improve the accuracy of location
Reduce the tendency to over-index
Improve upon the acceleration and deceleration characteristics
Reduce the cycle time
The ductile materials, during machining, produce
Continuous chips
Discontinuous chips
Continuous chips with built up edge
Either (A) or (C)
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
Flank wear occurs mainly on the
Nose part, front relief face and side relief face of the cutting tool
Face of the cutting tool at a short distance from the cutting edge
Cutting edge only
Front face only
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
Lathe bed is made of
Mild steel
Alloy steel
Pig iron
Chilled cast iron
A broach has
Roughing teeth
Semi-finishing teeth
Finishing teeth
All of these
In a single point turning operation with a cemented carbide and steel combination having a Taylor exponent of 0.25, if the cutting speed is halved, then tool life will become
Half
Two times
Eight times
Sixteen times
The usual value of the point angle of a drill is
70°
100°
118°
130°
The chuck used for setting up of heavy and irregular shaped work should be
Four jaw independent chuck
Three jaw universal chuck
Magnetic chuck
Drill chuck
The factor responsible for the formation of discontinuous chips is
Low cutting speed and large rake angle
Low cutting speed and small rake angle
High cutting speed and large rake angle
High cutting speed and small rake angle
Climb milling is chosen while machining because
The chip thickness increase gradually
It enables the cutter to dig in and start the cut
The specific power consumption is reduced
Better surface finish can be obtained
The cutting speed for counter-boring should be _________ that of drilling operation.
Equal to
Less than
Greater than
None of these
High speed steel tools retain their hardness upto a temperature of
250°C
350°C
500°C
900°C
In _________ operation, the chip thickness is minimum at the beginning of the cut and it reaches to the maximum when the cut terminates.
Conventional milling
Climb milling
Face milling
End milling
Gear finishing operation is called
Shaping
Milling
Hobbing
Burnishing
The operation of producing grooves around the periphery of a cylindrical or conical workpiece is called
Profile milling
Gang milling
Saw milling
Helical milling
For fast removal of materials during grinding, a _________ grinding wheel is used.
Course grained
Fine grained
Medium grained
None of these
The parameter which completely defines the chip formation in a metal cutting process is
Shear angle
Chip-tool contact length
Both (A) and (B)
None of these
A jig is defined as a device which
Holds and locates a workpiece and guides and controls one or more cutting tools
Holds and locates a workpiece during an inspection or for a manufacturing operation
Is used to check the accuracy of workpiece
All of the above
The tail stock set over method of taper turning is preferred for
Internal tapers
Small tapers
Long slender tapers
Steep tapers
A lathe with four steps on the cone pulley and with back-gears will have
Four direct speeds
Four indirect speeds
Four direct and four indirect speeds
Eight indirect speeds
In a milling operation, two side milling cutters are mounted with a desired distance between them so that both sides of a workpiece can be milled simultaneously. This set up is called
Gang milling
Straddle milling
String milling
Side milling
Side relief angle of a single point tool is the angle
By which the face of the tool is inclined towards back
By which the face of the tool is inclined sideways
Between the surface of the flank immediately below the point and a plane at right angles to the centre line of the point of tool
Between the surface of the flank immediately below the point and a line drawn from the point perpendicular to the base
A tool used to withdraw a drill from the sleeve is called
Drill remover
Drill puller
Drift
Drill drawer
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