Machining
GATE Mechanical Engineering · 86 questions across 32 years (1987-2025) · 80% recurrence rate
Recurrence sparkline
1987–2025Difficulty mix
Question types
All 86 questions on Machining
Cylindrical workpieces of diameter 60 mm and length 400 mm are machined on a lathe at a cutting speed of $25 \mathrm{~m} \mathrm{~min}^{-1}$ and a feed of $0.2 \mathrm{~mm} \mathrm{rev}^{-1}$. The Taylor's tool life para...
A cutting tool provides a tool life of 60 minutes while machining with the cutting speed of 60 m/min. When the same tool is used for machining the same material, it provides a tool life of 10 minutes for a cutting speed...
A 1 mm thick cylindrical tube, 100 mm in diameter, is orthogonally turned such that the entire wall thickness of the tube is cut in a single pass. The axial feed of the tool is 1 m/minute and the specific cutting energy...
Under orthogonal cutting condition, a turning operation is carried out on a metallic workpiece at a cutting speed of 4 m/s. The orthogonal rake angle of the cutting tool is 5º. The uncut chip thickness and width of cut a...
In an orthogonal machining operation, the cutting and thrust forces are equal in magnitude. The uncut chip thickness is 0.5 mm and the shear angle is 15°. The orthogonal rake angle of the tool is 0° and the width of cut...
During the turning of a $$20$$ $$mm-$$diameter steel bar at a spindle speed of $$400$$ $$rpm,$$ a tool life of $$20$$ minute is obtained. When the same bar is turned at $$200$$ $$rpm,$$ the tool life becomes $$60$$ $$min...
Two cutting tools with tool life equations given below are being compared: $$\eqalign{ & Tool\,\,1:\,\,\,\,\,\,\,V{T^{0.1}} = 150 \cr & Tool\,\,2:\,\,\,\,\,\,\,V{T^{0.3}} = 300 \cr} $$ where $$V$$ is cutting speed in $$m...
In an orthogonal machining with a tool of $${9^ \circ }$$ orthogonal rake angle, the uncut chip thickness is $$0.2$$ $$mm.$$ The chip thickness fluctuates between $$0.25$$ $$mm$$ and $$0.4$$ $$mm.$$ The ratio of the maxi...
In a single point turning operation with cemented carbide tool and steel work piece, it is found that the Taylor's exponent is $$0.25.$$ If the cutting speed is reduced by $$50\% $$ then the tool life changes by ________...
In an orthogonal cutting process the tool used has rake angle of zero degree. The measured cutting force and thrust force are $$500$$ $$N$$ and $$250$$ $$N,$$ respectively. The coefficient of friction between the tool an...
For a certain job, the cost of metal cutting is $$Rs.18C/V$$ and the cost of tooling is Rs.$$270C/(TV).$$ Where $$C$$ is a constant, $$V$$ is the cutting speed in $$m/min$$ and $$T$$ is the tool life in minutes. The Tayl...
For an orthogonal cutting operation, tool material is $$HSS,$$ rake angle is $${22^ \circ },$$ chip thickness is $$0.8$$ $$mm,$$ speed is $$48$$ $$m/min$$ and feed is $$0.4$$ $$mm/rev$$. The shear plane angle (in degrees...
Under certain cutting conditions, doubling the cutting speed reduces the tool life to $${\left( {{1 \over {16}}} \right)^{th}}$$ of the original. Taylor’s tool life index $$(n)$$ for this tool workpiece combination will...
An orthogonal turning operation is carried out under the following conditions; rake angle $$ = {5^ \circ },$$ spindle rotational speed $$=400$$ $$rpm,$$ axial feed $$=0.4$$ $$m/min$$ and radial depth of $$cut = 5mm$$. Th...
Orthogonal turning of a mild steel tube with a tool of rake angle $${10^0}$$ is carried out at a feed of $$0.14$$ $$mm/rev.$$ If the thickness of the chip produced is $$0.28mm,$$ the values of shear angle and shear strai...
A single point cutting tool with $${0^0}$$ rake angle is used in an orthogonal machining process. At a cutting speed of $$180$$ $$m/min$$ the thrust force is $$490N.$$ If the coefficient of friction between the tool and...
If the Taylor's tool life exponent $$n$$ is $$0.2,$$ and the tool changing time is $$1.5$$ $$min,$$ then the tool life (in min) for maximum production rate is ____________
The main cutting force acting on a tool during the turning (orthogonal cutting) operation of a metal is $$400N.$$ The turning was performed using $$2mm$$ depth of cut and $$0.1mm/rev$$ feed rate. The specific cutting pre...
Which pair of following statement is correct for orthogonal cutting using a single-point cutting tool? $$P.$$ reduction in friction angle increases cutting force $$Q.$$ Reduction in friction angle decreases cutting force...
A straight turning operation is carried out using a single point cutting tool on an $$AISI$$ $$1020$$ steel rod. The feed is $$0.2$$ $$mm/rev$$ and the depth of cut is $$0.5$$ $$mm.$$ The tool has a side cutting edge ang...
Better surface finish is obtained with a large rake angle because
Cutting tool is much harder than the work piece. Yet the tool wears out during the tool-work interaction, because
During pure orthogonal turning operation of a hollow cylindrical pipe, it is found that the thickness of the chip produced is $$0.5mm.$$ The feed given to the zero degree rake angle tool is $$0.2mm/rev.$$ The shear strai...
In orthogonal turning of a bar of $$100$$ $$mm$$ diameter with a feed of $$0.25$$ $$min/rev,$$ depth of cut of $$4$$ $$mm$$ and cutting velocity of $$90$$ $$m/min,$$ it is observed that the main (tangential) cutting forc...
Two cutting tools are being compared for a machining operation. The tool life equations are: $$\eqalign{ & \,\,\,\,\,\,\,\,\,\,\,\,Carbi{\mathop{\rm de}\nolimits} \,\,tool:\,\,\,\,\,\,\,\,\,\,\,\,V{T^{1.6}} = 3000 \cr &...
In orthogonal turning of a bar of $$100$$ $$mm$$ diameter with a feed of $$0.25$$ $$min/rev,$$ depth of cut of $$4$$ $$mm$$ and cutting velocity of $$90$$ $$m/min,$$ it is observed that the main (tangential) cutting forc...
A single-point cutting tool with $${12^0}$$ rake angle is used to machine a steel work-piece. The depth of cut, $$i.e$$ uncut thickness is $$0.81$$ $$mm.$$ The chip thickness under orthogonal machining condition is $$1.8...
For tool $$A,$$ Taylor’s tool life exponent $$(n)$$ is $$0.45$$ and constant $$(K)$$ is $$90.$$ Similarly for tool $$B,$$ $$n=0.3$$ and $$K=60.$$ The cutting speed (in $$m/min$$) above which tool $$A$$ will have a higher...
The minimum shear strain in orthogonal turning with a cutting tool of zero rake angle is
Friction at the tool - chip interface can be reduced by
Orthogonal turning is performed on a cylindrical work piece with shear strength of $$250Mpa.$$ The following conditions are used: cutting velocity is $$180m/min,$$ feed is $$0.2mm/rev,$$ depth of cut is $$3mm,$$ chip thi...
In a single point turning tool, the side rake angle and orthogonal rake angle are equal. $$\varphi $$ is the principle cutting edge angle and its range is $$0$$ to $$90.$$ The chip flows in the orthogonal plane. The valu...
Orthogonal turning is performed on a cylindrical work piece with shear strength of $$250Mpa.$$ The following conditions are used: cutting velocity is $$180m/min,$$ feed is $$0.2mm/rev,$$ depth of cut is $$3mm,$$ chip thi...
In orthogonal turning of low carbon steel pipe with principal cutting edge angle of $$90,$$ the main cutting force is $$1000$$$$N$$ and the feed force is $$800N.$$ The shear angle is $$25$$ and orthogonal rake angle is z...
In orthogonal turning of a low carbon steel bar of diameter $$150mm$$ with uncoated carbide tool, the cutting velocity is $$90m/min,$$ The feed is $$0.24mm/rev$$ and the depth of cut is $$2mm.$$ The chip thickness obtain...
In orthogonal turning of medium carbon steel, the specific machining energy is $$2$$ $$kJ/m{m^3},$$ the cutting velocity, feed and depth of cut are $$120m/min,$$ $$0.2mm/rev$$ and $$2mm$$ respectively. The main cutting f...
A low carbon steel bar of $$147$$ $$mm$$ diameter with length of $$630$$ $$mm$$ is being turned with uncoated carbide insert. The observed tool lives are $$24$$ and $$12$$ for cutting velocities of $$90$$ $$m/min$$ and $...
A low carbon steel bar of $$147$$ $$mm$$ diameter with length of $$630$$ $$mm$$ is being turned with uncoated carbide insert. The observed tool lives are $$24$$ and $$12$$ for cutting velocities of $$90$$ $$m/min$$ and $...
In an orthogonal machining operation: $$\,\,\,\,\,\,\,\,\,\,$$Uncut thickness $$\,\,\,\,\,$$ $$= 0.5$$ $$mm$$ $$\,\,\,\,\,\,\,\,\,\,$$Cutting speed $$\,\,\,\,\,\,\,\,\,\,$$ $$= 20$$ $$m/min$$ $$\,\,\,\,\,\,\,\,\,\,$$Widt...
In an orthogonal machining operation: $$\,\,\,\,\,\,\,\,\,\,$$Uncut thickness $$\,\,\,\,\,$$ $$= 0.5$$ $$mm$$ $$\,\,\,\,\,\,\,\,\,\,$$Cutting speed $$\,\,\,\,\,\,\,\,\,\,$$ $$= 20$$ $$m/min$$ $$\,\,\,\,\,\,\,\,\,\,$$Widt...
In an orthogonal machining operation: $$\,\,\,\,\,\,\,\,\,\,$$Uncut thickness $$\,\,\,\,\,$$ $$= 0.5$$ $$mm$$ $$\,\,\,\,\,\,\,\,\,\,$$Cutting speed $$\,\,\,\,\,\,\,\,\,\,$$ $$= 20$$ $$m/min$$ $$\,\,\,\,\,\,\,\,\,\,$$Widt...
Two tools $$P$$ and $$Q$$ have signature $${5^ \circ } - {5^ \circ } - {6^ \circ } - {6^ \circ } - {8^ \circ } - {30^ \circ } - 0$$ and $${5^ \circ } - {5^ \circ } - {7^ \circ } - {7^ \circ } - {8^ \circ } - {15^ \circ }...
In a machining operation, doubling the cutting speed reduces the tool life to $$1/{8^{th}}$$ of the original value. The exponent $$n$$ in Taylor's tool life equation $$V{T^n} = C,$$ is
In an orthogonal cutting test on mild steel, the following data were obtained Cutting speed: $$40$$ $$m/min,$$ Depth of cut: $$0.3$$ $$mm,$$ Tool rake angle : $$ + {5^ \circ },$$ Chip thickness: $$1.5$$ $$mm,$$ Cutting f...
A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $$200rpm$$. The axial feed rate is $$0.25$$ $$mm$$ per revolution. Depth of cut is $$0.4mm.$$ The rake angle is $${10^ \circ }.$$ In...
A batch of $$10$$ cutting tools could produce $$500$$ components while working at $$50$$ $$rpm$$ with a tool feed of $$0.25$$ $$mm/rev$$ and depth of cut of $$1$$ $$mm.$$ A similar batch of $$10$$ tools of the same speci...
A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $$200rpm$$. The axial feed rate is $$0.25$$ $$mm$$ per revolution. Depth of cut is $$0.4mm.$$ The rake angle is $${10^ \circ }.$$ In...
Formation on build-up edge during machining can be avoided by using
A good cutting fluid should have
A tube of $$32mm$$ outside diameter was turned on a lathe and the following data was obtained Rake angle $$=35deg,$$ Feed rate $$=0.1mm/rev$$ Cutting force $$=2000N,$$ Cutting speed $$=15m/min$$ Length of continuous chip...
$$BUE$$ is formed while machining
During orthogonal cutting of mild steel with a $$10$$ degrees rake angle tool the chip thickness ratio was obtained as $$0.4.$$ The shear angle (in degrees) evaluated from this data is
Tool life testing on a lathe under dry cutting conditions gave $$'n'$$ and $$'C'$$ of Taylor tool life equation as $$0.12$$ and $$130$$ $$m/min,$$ respectively. When a coolant was used, $$'C'$$ increased by $$10\% $$. Th...
Identical straight turning operation was carried out using two tools : $$8 - 8 - 5 - 5 - 5 - 25 - 0\,(ASA)$$ and $$8-8-5-5-7-30-0(ASA)$$. For same feed the tool which gives better surface finish is
For turning $$NiCr$$ alloy steel at cutting speeds of $$64m/min$$ and $$100m/min,$$ the respective tool lives are $$15min$$ and $$12$$ $$min.$$ The tool life for a cutting speed of $$144m/min$$ is
A built up edge is formed while machining
The lives of two tools $$A$$ & $$B$$, governed by the equation $$V{T^{0.125}} = 2.5$$ and $$V{T^{0.25}} = 7$$ respectively in certain machining operation where $$V$$ is the cutting velocity in $$m/s$$ and $$T$$ is the to...
In an orthogonal cutting experiment with a tool of rake angle $$7$$$$deg$$, the chip thickness was found to be $$2.5mm$$ when the uncut chip thickness was set to $$1mm,$$ find the shear angle $$\phi $$ and find the frict...
What is the approximate $$\% $$ change in the life, $$t,$$ of the tool with zero rake angle used in orthogonal cutting when its clearance angle, $$\alpha ,$$ is changed from $$10$$ to $$7$$ deg? (Hint: flank wear rate is...
In orthogonal machining operation, the chip thickness and the uncut chip thickness are equal to $$0.45mm$$. If the tool rake angle is $$0$$ deg. The shear plane angle is
A Throwaway carbide insert was used to machine a steel work pieces with a cutting speed of $$60$$ $$m/min,$$ tool life of $$40$$ minutes was observed, when the cutting speed was increased to $$100$$ $$m/min,$$ the tool l...
In a typical metal cutting operation, using a cutting tool of positive rake $$\gamma = 10\deg ,$$ it was observed that the shear angle was $$20deg$$. The friction angle is
In a turning trail using orthogonal tool geometry, a chip length of $$84mm$$ was obtained for an uncut chip length of $$200mm.$$ The cutting conditions were $$V=30m/min,$$ $${t_1} = 0.5mm,$$ rake angle $$=20deg,$$ cuttin...
Tool life of a $$10$$ hours is obtained when cutting with a single point tool at $$63m/min.$$ If Taylor's constant $$C=257.35,$$ tool life on doubling the velocity will be
A single point turning tool is designated as $$${10^ \circ } - {12^ \circ } - {7^ \circ } - {5^ \circ } - {20^ \circ } - {50^ \circ } - {0^ \circ }\left( {ORS} \right)$$$ The values of normal rake and normal clearance of...
Cutting power consumption in turning can be signification reduced by
While turning a $$C15$$ steel of $$160mm$$ diameter at $$215rpm,$$ $$2.5mm$$ depth of cut and feed of $$0.16mm/rev$$ by a tool of geometry $$0-10-8-9-15-75-0mm,$$ the following observations were made. Tangential componen...
If under a condition of plain turning the life of the cutting tool decreases by $$50\% $$ due to increase in the cutting velocity by $$20\% $$, then what is the $$\% $$ increase in tool life due to reduction in the cutti...
A single point cutting tool made of $$HSS$$ has the value of constant $$'C'$$ $$80,$$ and $$n=0.2$$ in the basic tool life equation. If the tool cost per regrind is Rs $$2$$ and the vmachine hour rate is Rs. $$30,$$ dete...
In an orthogonal cutting operation on a work piece of width $$2.5mm,$$ the uncut chip thickness was $$0.25$$ $$mm$$ and the tool rake angle was $$0$$(zero) degrees. It was observed that the chip thickness was $$1.25mm.$$...
The effect of rake angle on the mean friction angle in machining can be explained by
Find the percentage change in cutting speed required to give a $$50\% $$ reduction in tool life (that is required tool life is half of the original tool life ) when the value of the tool life exponent $$n=0.125$$ or $$1/...
Calculate the $$MRR$$ and Specific cutting pressure for the following cutting conditions Work material : steel, Tool material : $$HSS,$$ Depth of cut : $$1.6mm,$$ Feed : $$0.8mm/rev$$ Cutting speed $$=5.5m/min$$ and powe...
Most of the metal cutting heat goes into the
Determine the Merchants constant $$'C'$$ (shear angle relation) for aluminium from the following orthogonal machining data. Rake angle $${35^ \circ }$$ and an uncut chip thickness $$0.15mm,$$ the values of $${F_c}$$ and...
A tube is orthogonally machined in lathe to reduce its length under the following conditions. Outside diameter of the tube : $$100mm,$$ Inside diameter of the tube $$=96$$ $$mm$$ $$RPM$$ of the work piece $$=120,$$ Longi...
Most of the metal cutting heat goes into the
The cutting tool are being tried for an operation. Tailors tool life equation for them are as follows $$\eqalign{ & HSS\,\,tool\,:\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,V{T^{0.1}} = 200 \cr & Carbide\,\,tool\,:\,\,\,\,\,\,\,V{T^{...
In an orthogonal cutting test on the following data were obtained Uncut chip thickness $$=0.25mm,$$ Cutting speed: $$60m/min,$$ Tool rake angle: $$0$$ Chip thickness $$0.75mm,$$ Cutting force : $$900$$ $$N$$, Thrust forc...
Crater wear always starts at some distance from the tool tip because at that point
The size of $$BLUE$$ in metal cutting increases with
Pure metal pose machinability problem in turning operations. The reason is the
The ideal cutting fluid for low speed machining of metals should be one which
During orthogonal turning of a steel rod by zero rake tool at feed $$0.25mm/rev$$ and depth of cut $$2.0mm,$$ the following observations were obtained. Tangential component of cutting force $$=1000N$$, Axial component of...
Cutting tools are provided with large positive rake angle mainly for
In a turning operation the tool life of the carbide tool was found to be $$20min$$ and $$100min,$$ at cutting speeds of $$120m/min$$ and $$80m/min$$ respectively. What will be the tool life of the tool under same conditi...