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Linked Question

A low carbon steel bar of $147mm$ diameter with a length of $630mm$ is being turned with an uncoated carbide insert. The observed tool lives are $24min$ and $12min$ for cutting velocities of $90m/min$ and $120m/min$ respectively. The feed and depth of cut are $0.2mm/rev$ and $2mm$ respectively. Use the unmachined diameter to calculate the cutting velocity.



When tool life is $20min$ the cutting velocity in $m/min$ is

A tool with side cutting edge angle of ${30}^o$ and end cutting edge angle ${10}^o$ is used for fine turning with a feed of $1mm/rev$. Neglectign nose redius of the tool, the maximum (peak of valley) height of the surface roughness produced will be

A hemispherical cup of radius $R$ is formed in a press-working operation. The radius of blank would be

A bar of 75 mm diameter is machined to reduce its diameter by orthogonal cutting. If the length of the cut chip is 73.5 mm and rake angle is ${15}^{\circ },$ the shear plane angle is

A single-point cutting tool with ${12}^o$ rake angle is used to machine a steel work-piece. The depth of cut, i.e., uncut thickness is $0.81mm$. The chip thickness under orthogonal machining condition is $1.8mm$. The shear angle is approximately.

1. 0.504

Linked Data:

In a orthogonal cutting experiment, an HSS tool having the following tool signature in the orthogonal reference system (ORS) has been used : $0-10-7-710-75-1$

Given: Width of cut $=3.6mm$ Shear strength of workpiece material $=460N/m{m}^2$; Depth of cut $=0.25mm$ Coefficient of friction at chip tool interface $=0.7$



Minimum power requirement (in $kW$) at a cutting speed of $150m/mm$ is

Determine the load required to punch a $20mm$ diameter hole in a $2mm$ thick sheet. The properties of the material of the sheet are:

Tensile strength $-580MPa$

Yield strength in tension $-410MPa$

Shear strength $-350MPa$

Yield strength in shear $-250MPa$

The load is $kN$ is

1. 2.1

A workpiece of $100cm$ length and $30cm$ width is machined by planning operation with a feed of $0.3mm/stroke$. The machine tool executes $10$ double strokes per minute. The planning time for a single pass is

Common Data Question

A cup is to be drawn to a diameter of $70mm$ with $35mm$ depth from a $0.5mm$ thick sheet metal. The cup is drawn in one operation. Assume ${\sigma }_u=430MPa$



The required blank diameter is

The following data relate to an orthogonal turning process: back rake angle $=15deg.$ width of cut $=2mm$ chip thickness $=0.4mm$ feed rate $=0.2mm/rev$



The shear angle is

Linked Data:

Blind hole $10mm$ diameter, $50mm$ deep are being drilled in steel block, drilling spindle speed is $600rpm$, feed $0.2mm/rev,$ point angle of drill is $120$



During the above operation, the drill wears out after producing $200$ holes.Taylor's tool life equation is of the form $V{T}^{0.3}=C,$ where $V=$ cutting speed in $m/min$ and $T=$ tool life in min. Taylor's constnat $C$ will be

1. 2.5

In orthogonal machining operation, the chip thickness and the uncut chip thickness are equal to $0.45mm$. If the tool rake and is $0$ deg. The shear plane angle is

Linked Data:

During orthogonal machining of a mild steel specimen with a cutting tool of zero rake angle, the following data is obtained:

Uncut chip thickness $=0.25mm$

Chip thickness $=0.75mm$

Normal force $=950N$

thrust force $=475N$



The shear angle and shear force, respectively, are

Linked Data:

A $\varphi 40mm$ job is subjected to orthogonal turning by $a+{10}^o$ rake angle tool at $500rev/min$. By direct measurement during the cutting operation, the shear angle was found equal to ${25}^o$



If the friction angle at the tool chip interface is ${58}^o{10}^{\prime }$ and the cutting force components measured by a dynamometer are $600N$ and $200N$ the power loss due to friction (in $kNm/min$) is approximately

In a shaping process, the number of double strokes per minute is $30$ and the quick return ratio is $0.6$. If the length of the stroke is $250mm$ the average cutting velocity in $mm/min$.

The main cutting force acting on a tool during the turning (orthogonal cutting) operation of metal is $400N$. The turning was performed using $2mm$ depth of cut and $0.1mm/rev$ feed rate. The specific cutting pressure (in $N/m{m}^2$) is

During orthogonal cutting of $MS$ with a $10deg$ rake angle tool, the chip thickness ratio was obtained as $0.4$. The shear angle (in degrees) evaluated from this data is

In a AJM process, if Q= flow rate of abrasives and d = mean diameter of the abrasives, then MRR is proportional to

1. 0.0124

In an orthogonal metal cutting process are given below



Chip thickness = 0.8 mm

Undeformed thickness = 0.6 mm

Rake angle = ${15}^o$

Cutting speed = 2.5 m/s



Mean thickness of primary shear zone 25 microns then the shear strain rate is $\left(s^{-1}\right)$ during the process is

In an orthogonal cutting test on mild steel, the following data were obtained

Cutting speed : $40m/min$

Depth of cut : $0.3mm$

Total rake angle : $+5^o$

Chip thickness : $1.5mm$

Cutting force : $900N$

Thrust force : $450N$

Using Merchant's analysis, the friction angle during the machining will be

A steel bar $200mm$ in a diameter is turned at a feed of $0.25mm/rev$ With a depth of cut of $4mm$ The rotational speed of the workpiece is $160rpm$. The material removal rate in $m{m}^3/s$ is

A milling cutter having $8$ teeth is rotating at $150rpm$. If the feed per tooth is $0.1mm$, the speed in $mm$ per minute is

The following data relate to an orthogonal turning process: back rake angle $=15deg.$ width of cut $=2mm$ chip thickness $=0.4mm$ feed rate $=0.2mm/rev$



If the cutting force and the thrust force are $900N$ and $810N$ the shear strength in $MPa$

In an orthogonal cutting test with a tool of rake angle 15 deg, the following observations were made: chip thickness ratio = 0.37, horizontal cutting force = 1000 N, vertical cutting force = 1500 N.



The machining constant for the given machining operation is

1. 5

1. 274.89

A hole of $40mm$ diameter is pierced in a steel sheet of $4mm$ thickness without shear on the tool. Shear strength of steel is $400N/m{m}^2$ and penetration is $25$%. What is the expected percentage load reduction if a shear of $1mm$ is provided on the punch?

1. -60.78

1. 4857

A hole of $20mm$ diameter is to be drilled in a steel block of $40mm$ thickness. The drilling is performed at rotational speed of $400rpm$ and feed rate of $0.1mm/rev$. The required approach and over run of the drill together is equal to the radius of the drill. The drilling time (in minute) is

In an orthogonal cutting test, the following observation were made

Cutting force $=1200N$

Thrust force $=500N$

Tool rake angle $=zero$

Cutting speed $=1m/s$

Depth of cut $=0.8mm$

Chip thickness $=1.5mm$



Chip speed along the tool rake face will be

A cutting tool can be designated as:

$5-8-12-9-25-53-0.2$ mm.

(ORS) is used for machining. The normal rake angle of the tool is

Linked Data:

A $\varphi 40mm$ job is subjected to orthogonal turning by $+{10}^o$ rake angle tool at $500rev/min$. By direct measurement during the cutting operation, the shear angle was found equal to ${25}^o$.



The velocity (in $m/min$) with which the chip flows on the tool face is

Common Data:

In an orthogonal machining operation:

Uncut thickness $=0.5mm$

Cutting speed $=20m/min$

Rake angle $={15}^o$

Width of cut $=5mm$

Chip thickness $=07mm$

Thrust force $=200N$

Cutting force $=1200N$

Assume Merchant's theory.



The coefficient of friction at the tool-chip interface is

For turning $NiCr$ alloy steel at cutting speeds of $64m/min$ and $100m/min$, the respective tool lives are $15min$ and $12min$. The tool life for a cutting speed of $144m/min$ is

In orthogonal turning of medium carbon steel, the specific machining energy is $2.J/m{m}^3$. The cutting velocity, feed and depth of cut are $120m/min,0.2mm/rev$ and $2mm$ respectively. The main cutting force in $N$ is

In a machining operation, doubling the cutting speed reduces the tool life to $1/8^{th}$ of the original value. The exponent $n$ in Taylor's tool life equation $V{T}^n=C$, is

Tool life equations for two tools under consideration are as follows

$HSS:V{T}^{0.2}=150$

$Carbide:V{T}^{0.3}=250$

Where $V$ is the cutting speed in $m/min$ and $T$ is the tool life in $min$. The breakeven cutting speed above which the carbide tool will be beneficial is

1. 1410

Common Data:

A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $200rpm$. The axial feed rate is $0.25mm$ per revolution. Depth of cut is $0.4mm$ The rake angle is ${10}^o$. In the analysis it is found that the shear angle is ${27.75}^o$.



In the above problem, the coefficient of friction at the chip tool interface obtained using Earnest and Merchant theory is

A batch of $500$ jobs of diameter $50mm$ and length $100mm$ is to be turned at $200rev/min$ and feed $0.2mm/rev$



The number of tool changes required to machine the whole batch is

A hydraulic press is used to produce circular blanks of $100mm$ diameter from a sheet o $2mm$ thickness. If the shear strength of the sheet material is $400N/m{m}^2$, the force required for producing a circular blank is

1. 18.88

Linked Data:

In a orthogonal cutting experiment, an HSS tool having the following tool signature in the orthogonal reference system (ORS) has been used : $0-10-7-7-10-75-1$

Given: Width of cut $=3.6mm$

Shear strength of workpiece material $=460N/m{m}^2$; Depth of cut $=0.25mm$ Coefficient of friction at chip tool interface $=0.7$



Shear plane angle (in degrees) for minimum cutting force is

Common Data:

A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $200rpm$. The axial feed rate is $0.25mm$ per revolution. Depth of cut is $0.4mm$ The rake angle is ${10}^o$. In the analysis it is found that the shear angle is ${27.75}^o$.



The thickness of the produced chip is

A non standard thread of pitch $3.175mm$ is to be cut on a lathe having lead screw of pitch $6mm$. A change gear set provdied with the lathe has one gear each with the following number of teeth: $20,30,40,50,60,70,80,90,100,110,120,127.$ The correct pairs of change gears $(a/b\times c/d)$ for machining the given thread are (assuming that transmission ratio of the rest of the kinematic train between the late spindle and lead screw is equal to 1)