The carbide tools operating at very low cutting speeds (below 30 m/min)
Reduces tool life
Increases tool life
Have no effect on tool life
Spoils the work piece
Correct Answer :
A. Reduces tool life
Related Questions
The facing 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
Machining the ends of a workpiece to produce a flat surface square with the axis
A shaft has a dimension, φ9 +0.025⁺⁰⁰⁰⁹, the respective values of fundamental deviation and tolerance are
- 0.025, ±0.008
- 0.025, 0.016
- 0.009, ± 0.008
- 0.009, 0.016
Flank wear depends upon the
Hardness of the work and tool material at the operating temperature
Amount and distribution of hard constituents in the work material
Degree of strain hardening in the chip
All of these
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
The size of a lathe is specified by the
Length between centres
Swing diameter over the bed
Swing diameter over the carriage
All of these
In order to obtain a surface finish in the range of 0.75 μm to 1.25 μm , the operation used is called.
Grinding
Lapping
Honing
Buffing
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
The enlarging of an existing circular hole with a rotating single point tool is called
Boring
Drilling
Reaming
Internal turning
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
The usual value of the helix angle of a drill is
20°
30°
45°
60°
In an interchangeable assembly, shafts of size 25.000 -0.010⁺⁰⁰⁴⁰ mm mate with holes of size 25.000 -0.020⁺⁰⁰³⁰, the maximum interference (in microns) in the assembly is
40
30
20
10
In a gating system, the ratio 1: 2: 4 represents
Sprue base area: runner area: ingate area
Pouring basin area: ingate area: runner area
Sprue base area: ingate area: casting area
Runner area: ingate area: casting area
The cutting speed is minimum while machining _________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
Which of the following statement is wrong as regard to down milling?
It can not be used on old machines due to backlash between the feed screw of the table and the nut.
The chips are disposed off easily and do not interfere with the cutting.
The surface milled appears to be slightly wavy.
The coolant can be poured directly at the cutting zone where the cutting force is maximum.
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
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 point angle of a drill, for drilling stainless steel, is
90°
118°
135°
150°
In ECM, the material removal is due to
Corrosion
Erosion
Fusion
Ion displacement
A process of removing metal by pushing or pulling a cutting tool is called
Up milling
Down milling
Forming
Broaching
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
The operation of machining several surfaces of a workpiece simultaneously is called
Profile milling
Gang milling
Saw milling
Helical milling
Tool signature consists of __________ elements.
Two
Four
Five
Seven
The cutting speed for drilling aluminium, brass and bronze 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
The hole to be drilled for tapping is _________ the outside diameter of the thread on the tap.
Equal to
Smaller than
Greater than
None of these
The top and sides of the table of a shaper usually have
L-type slots
T-type slots
I-type slots
Any one of these
Two 1 mm thick steel sheets are to be spot welded at a current of 5000 A. Assuming effective resistance to be 200 μm and current flow time of 0.2 second, heat generated during the process will be
0.2 Joule
1 Joule
5 Joule
1000 Joule
The mechanism of material removal in EDM process is
Melting and Evaporation
Melting and Corrosion
Erosion and Cavitations
Cavitations and Evaporation
For generating a Coons surface we require
A set of grid points on the surface
A set of grid control points
Four bounding curves defining the surface
Two bounding curves and a set of grid control points
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
Relief angles on high speed steel tools usually vary from
0° to 3°
3° to 10°
10° to 20°
20° to 30°