High speed steel tools retain their hardness upto a temperature of
250°C
350°C
500°C
900°C
Correct Answer :
D. 900°C
Related Questions
Which of the following statement is correct for oblique cutting system?
The cutting edge is inclined at an angle less than 90° with the normal to the velocity of the tool.
Frequently, more than one cutting edges are in action.
The chip flows on the tool face at an angle less than 90° with the normal on the cutting edge.
All of the above
The capacity of a material to be welded under the imposed fabrication conditions into a specific, suitably designed structure and to perform satisfactorily in the intended service is known as?
Weldment
Weld tab
Weldability
Tack weld
The chamfering is an operation of
Bevelling the extreme end of a workpiece
Embossing a diamond shaped pattern on the surface of a workpiece
Reducing the diameter of a workpiece over a very narrow surface
Enlarging the end of a hole cylindrically
The guideways are of
Flat type
V-type
Dovetail type
Any one of these
In electro discharge machining, tool is made of
Brass
Copper
Copper tungsten alloy
All of these
Crater wear is predominant in
Carbon tool steels
Tungsten carbide tools
High speed steel tools
Ceramic tools
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
The lip clearance angle is the angle formed by the
Leading edge of the land with a plane having the axis of the drill
Flank and a plane at right angles to the drill axis
Chisel edge and the lip as viewed from the end of a drill
None of the above
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 specific cutting energy used for establishing the machinability of the metal depends upon its
Coefficient of friction
Microstructure
Work hardening characteristics
All of these
In order to have interference fit, it is essential that the lower limit of the shaft should be
Greater than the upper limit of the hole
Lesser than the upper limit of the hole
Greater than the lower limit of the hole
Lesser than the lower limit of the hole
Carbide tipped tools usually have
Negative rake angle
Positive rake angle
Any rake angle
No rake angle
Gears can be best produced on mass production by
Shaping
Casting
Forming
Hobbing
The negative rake is usually provided on
High carbon steel tools
High speed steel tools
Cemented carbide tools
All of these
The angle between the lathe centres is
30°
45°
60°
90°
The structure of a grinding wheel depends upon
Hardness of the material being ground
Nature of the grinding operation
Finish required
All of these
Which of the following statement is correct about hot machining?
It requires less power than machining metals at room temperature.
The rate of tool wear is lower.
It is used for machining high strength and high temperature resistant materials.
All of the above
The grinding wheel speed (surface speed in m/min) usually varies from
500 to 1000
1000 to 1500
1500 to 2000
2000 to 2500
Discontinuous chips are formed during machining of
Brittle metals
Ductile metals
Hard metals
Soft metals
The tap used to cut threads in a blind hole is
Taper tap
Second tap
Bottoming tap
Any one of these
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
The cutting speed is maximum while machining __________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
The rake angle of a single point cutting tool corresponds to _________ of a twist drill.
Lip clearance angle
Helix angle
Point angle
Chisel edge angle
A drill bit of 20 mm diameter rotating at 500 r.p.m. with a feed rate of 0.2 mm/revolution is used to drill a through hole in a mild steel plate 20 mm thickness. The depth of cut in this drilling operation is
0.2 mm
10 mm
20 mm
100 mm
A fine grained grinding wheel is used to grind
Hard and brittle materials
Soft and ductile materials
Hard and ductile materials
Soft and brittle materials
The operation of smoothing and squaring the surface around a hole is known as
Counter-sinking
Counter-boring
Trepanning
Spot facing
An open structure of a grinding wheel is used for
Soft materials
Tough materials
Ductile materials
All of these
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 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
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