The main purpose of spheroidising treatment is to improve
Hardenability of low carbon steels
Machinability of low carbon steels
Hardenability of high carbon steels
Machinability of high carbon steels
Correct Answer :
D. Machinability of high carbon steels
Related Questions
A __________ grinding wheel is used to grind soft materials.
Course grained
Medium grained
Fine grained
None of these
In machining metal, cutting force at the cutting edge is measured by a
Wattmeter
Dynamometer
Hydrometer
Pyrometer
Hot rolling of mild steel is carried out
At recrystallization temperature
Between 100⁰C to 150⁰C
Between recrystallization temperature
Above recrystallization temperature
The in-feed grinding is used to
Produce tapers
Grind shoulders and formed surfaces
Grind long, slender shafts or bars
All of these
A 15 mm drilling machine means that it can drill a hole
Of maximum diameter 15 mm
In 15 mm thick plates
Having cross-sectional area of 15 mm²
None of these
The angle formed by the leading edge of the land with a plane having the axis of the drill, is called
Helix or rake angle
Point angle
Chisel edge angle
Lip clearance angle
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
In a shaper, the length of stroke is increased by
Increasing the centre distance of bull gear and crank pin
Decreasing the centre distance of bull gear and crank pin
Increasing the length of the arm
Decreasing the length of the slot in the slotted lever
Soft materials can not be economically ground due to
High temperature involved
Frequent wheel clogging
Rapid wheel wear
Low work piece stiffness
A hole is of dimension φ = 9 ₊0⁺⁰⁰¹⁵ mm. The corresponding shaft is of dimension φ = 9 ₊0.001⁺⁰⁰¹⁰ mm. The resulting assembly has
Loose running fit
Close running fit
Transition fit
Interference fit
The cutting speed is maximum while machining __________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
Cast iron during machining produces
Continuous chips
Discontinuous chips
Continuous chips with built-up edge
None of these
The operation performed on a shaper is
Machining horizontal surface
Machining vertical surface
Machining angular surface
All of these
Surface grinding is done to produce
Tapered surface
Flat surface
Internal cylindrical holes
All of these
Which of the following statement is correct regarding grinding of high carbon steel?
Grinding at high speed results in the reduction of chip thickness and cutting forces per grit.
Aluminium oxide wheels are employed.
The grinding wheel has to be of open structure.
All of the above
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
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
When the metal is removed by erosion caused by rapidly recurring spark discharges between the tool and work, the process is known as
Electrochemical machining
Electro-discharge machining
Ultrasonic machining
None 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
What is the type of welding defect caused due to poor manipulation of weld rod or a dirty joint called?
Porosity
Undercut
Under fill
Crack
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 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
Tool signature consists of __________ elements.
Two
Four
Five
Seven
The cutting speed for drilling aluminium, brass and bronze with carbon steel drills is _________ cutting speed for drilling mild steel with high speed steel drills.
Equal to
Less than
More than
None of these
If the tearing efficiency of a riveted joint is 50%, then ratio of rivet hole diameter to the pitch of rivets is
0.20
0.30
0.50
0.60
The snag grinding is done
To produce good surface finish and high degree of accuracy
To remove considerable amount of metal without regard to accuracy of the finished surface
To grind exterior cylindrical surfaces
Any one of the above
In grinding irregular, curved, tapered, convex and concave surfaces, the grinder used is
Cylindrical grinder
Internal grinder
Surface grinder
Tool and cutter grinder
The cutting speed is minimum while machining _________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
When two main plates are kept in alignment butting each other and riveted with cover plate on both sides of the main plates with two rows of rivets in each main plate, the joint is known as _______ double cover butt joint.
Single riveted
Double riveted
Both (A) and (B)
None of these
Side rake angle of a single point cutting 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 the tool
Between the surface of the flank immediately below the point and a line drawn from the point perpendicular to the base