The addition of lead, sulphur and phosphorus to low carbon steels, help to
Reduce built up edge
Break up chips
Improve machinability
All of these
Correct Answer :
D. All of these
Related Questions
For machining a mild steel workpiece using carbide tool, the maximum material will be removed at a temperature of
50°C
100°C
175°C
275°C
The relation between tool life (T) and cutting speed (V) is VTn = Constant. In this relation, the value of n depends upon
Work material
Tool material
Working conditions
Type of chip produced
Quality screw threads are produced by
Thread milling
Thread chasing
Thread cutting with single point tool
Thread casting
The taper on the lathe spindle is
1 in 10
1 in 15
1 in 20
1 in 30
In drilling operation, the metal is removed by
Shearing
Extrusion
Shearing and extrusion
Shearing and compression
Negative rakes are used for
Carbide tools
Heavy loads
Harder materials
All of these
Any number of equal divisions can be obtained on milling machine by
Direct indexing
Simple indexing
Compound indexing
Differential indexing
What is the type of welding defect caused due to poor deposition of weld rod is called?
Porosity
Undercut
Under fill
Crack
The tool material, for faster machining, should have
Wear resistance
Red hardness
Toughness
All of these
The in-feed grinding is used to
Produce tapers
Grind shoulders and formed surfaces
Grind long, slender shafts or bars
All of these
A grinding wheel becomes glazed (i.e. cutting edge takes a glasslike appearance) due to
Wear of bond
Breaking of abrasive grains
Wear of abrasive grains
Cracks on grinding wheel
The common welding error that occurs due to wrong speed, faulty preparation, and high / low current, improper electrode size is called?
Distortion
Warping
Porous weld
Poor fusion
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
The thrust force will increase with the increase in
Side cutting edge angle
Tool nose radius
Rake angle
End cutting edge angle
Trepanning is an operation of
Making a cone-shaped enlargement of the end of a hole
Smoothing and squaring the surface around a hole
Sizing and finishing a small diameter hole
Producing a hole by removing metal along the circumference of a hollow cutting tool
The relation between the tool life (T) in minutes and cutting speed (V) in m/min is (where n = An exponent, which depends upon the tool and workpiece, and C = A constant)
VnT = C
VTn = C
Vn/T = C
V/Tn = C
The operation of smoothing and squaring the surface around a hole is known as
Counter-sinking
Counter-boring
Trepanning
Spot facing
The helix angle of a drill is __________ for drilling brass.
Equal to 30°
Less than 30°
More than 30°
None of these
As the cutting speed increases, the tool cutting forces
Remain constant
Increases
Decreases
First increases and then decreases
A coarse grained grinding wheel is used to grind
Hard and brittle materials
Soft and ductile materials
Hard and ductile materials
Soft and brittle materials
For machining a mild steel workpiece by a high speed steel tool, the average cutting speed is
5 m/min
10 m/min
15 m/min
30 m/min
The height of each tooth of a broach is
Same throughout
In progressively decreasing order
In progressively increasing order
None of these
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 is minimum while machining _________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
The effective number of lattice points in the unit cell of simple cubic, body centred cubic, and face centred cubic space lattices, respectively, are
1, 2, 2
1, 2, 4
2, 3, 4
2, 4, 4
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
Thread grinding requires work speed from
1 to 3 m/min
5 to 10 m/min
10 to 14 m/min
14 to 20 m/min
Glazing in grinding wheels can be decreased by
Using a harder wheel or by increasing the wheel speed
Using a softer wheel or by decreasing the wheel speed
Using a harder wheel or by decreasing the wheel speed
Using a softer wheel or by increasing the wheel speed
Ultrasonic machining is best suited for
Tool steels
Sintered carbides
Glass
All of these
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