Machining · Machine Tools and Machining · GATE PI

Turning, drilling, boring and milling are commonly used machining operations. Among these, the operation (s) performed by a single point cutting tool is (are)

Which one of the following statements related to grinding process is INCORRECT?

Match the following:

Reaming is a process used for

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

Grinding ratio is defined as

The binding material used in cemented carbide cutting tools is

Which of the following powder production methods produces spongy and porous particles?

Reaming is primarily used for achieving

Which of following gear manufacturing processes is based on generation principle.

In the manufacture of twist drills, the shank is joined to the body of the drill using

The final finishing process for the surface plate made of cast iron which is used as a reference surface is

In a shaper machine, the mechanism for tool feed is

Tool life in the case of a grinding wheel is the time

The cutting portion of a drill is to be welded to its shank. The process best suited for this is

The drawing shows a machined shaft. The purpose of providing rounded grooves at $$M$$ and $$N$$ is to

Which one of the following is not a synthetic abrasive material

The flanks of teeth of rack-type gear cutter used for cutting involute gear profiles are:

In Whitworth quick return mechanism (used in shapers) the velocity of the $$ram$$ is maximum at

The material most commonly used for manufacturing of machine tool beds is

Reamers have usually even number of teeth so that the cutting forces on teeth are properly balanced.

A grinding wheel is said to be glazed if

A blind hole is better tapped with a tap having

In a grinding wheel marked with $$AA-48-L-7-V-25, L$$ refers to

The teeth of both external and internal spur gears can be cut on

Amount of energy consumption per unit volume of metal removal is maximum in

Reamer is designed to have even number of flutes to:

In turning operation the surface finish can be improved by decreasing

Abrasives are not used in

A schematic diagram of peripheral milling is shown in the Figure.

If $$t$$ is the depth of cut and $$d$$ is the diameter of the milling cutter, then the length of approach $$\left( {la} \right)$$ is expressed as

In drilling operation, a twist-drill of $$30$$ $$mm$$ diameter with point angle of $$118$$ degrees is used. If the $$CNC$$ command issued to execute the drilling operation is $$G90$$ $$G01$$ $$Z??$$ $$F20.$$ The datum is defined on the top surface of the work material and the approach distance is $$3$$ $$mm.$$ Then, to achieve a cylindrical hole depth of $$40$$ $$mm,$$ the $$Z$$ coordinate to be provided in the $$CNC$$ command, in $$mm,$$ is ______________.

In a slab milling operation, a cutter of $$75$$ $$mm$$ diameter with sufficient width is used to remove $$5$$ $$mm$$ thick material from a $$200$$ $$mm$$ long part in a single pass. The minimum length of travel, in $$mm,$$ for the cutter to engage and completely cut the part surface is ______________.

An $$HSS$$ drill of $$20mm$$ diameter with $$5mm$$ cone height is used to drill a through hole in a steel work-piece of $$50mm$$ thickness. Cutting speed of $$10m/min$$ and feed rate of $$0.3mm/rev$$ are used. The drilling time, in seconds, neglecting the approach and over travel, is ______________

A disc of $$200$$ $$mm$$ outer and $$80$$ $$mm$$ inner diameter is faced at a feed of $$0.1$$ $$mm/rev$$ with a depth of cut of $$1$$ $$mm.$$ The facing operation is undertaken at a constant cutting speed of $$90$$ $$m/min$$ in a $$CNC$$ lathe. The main (tangential) cutting force is $$200$$ $$N$$

Assuming approach and over-travel of the cutting tool to be zero, the machining time in $$min$$ is

A disc of $$200$$ $$mm$$ outer and $$80$$ $$mm$$ inner diameter is faced at a feed of $$0.1$$ $$mm/rev$$ with a depth of cut of $$1$$ $$mm.$$ The facing operation is undertaken at a constant cutting speed of $$90$$ $$m/min$$ in a $$CNC$$ lathe. The main (tangential) cutting force is $$200$$ $$N$$

Neglecting the contribution of the feed force towards cutting power, the specific cutting energy in $$J/m{m^3}$$ is

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 $$m/min$$ is

In a single pass drilling operation, a through hole of $$15$$ $$mm$$ diameter is to be drilled in a steel plate of $$50mm$$ thickness. Drill spindle speed is $$500epm,$$ feed is $$0.2mm/rev$$ and drill point angle is $${118^ \circ }.$$ Assuming $$2mm$$ clearance at approach and exit, the total drill time (in seconds) is

During orthogonal machining of a mild steel specimen with a cutting tool of zero rake angle, the following data is obtained:
Uncut chip thickness $$=0.25$$ $$mm$$
Chip thickness $$=0.75$$ $$mm$$
Width of cut $$=2.5$$ $$mm$$
Normal force $$=950$$ $$N$$
Thrust force $$=475$$ $$N$$

The ultimate shear stress (in $$N/m{m^2}$$) of the work material is

During orthogonal machining of a mild steel specimen with a cutting tool of zero rake angle, the following data is obtained:
Uncut chip thickness $$=0.25$$ $$mm$$
Chip thickness $$=0.75$$ $$mm$$
Width of cut $$=2.5$$ $$mm$$
Normal force $$=950$$ $$N$$
Thrust force $$=475$$ $$N$$

The shear angle and shear force, respectively, are

Match the following materials with their most appropriate application:

The number of defective produced by a six sigma process (in Parts per million) is

The quick return mechanism used in shaper has rocker arm drive of length $$200mm.$$ If the crank radius is $$50mm$$ and the offset between crank center and rocker arm pivot is $$20mm,$$ length of the stroke (in meters) is

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

Machining time (in min) per hole will be

Blind hole $$10mm$$ diameter, $$50mm$$ deep are being drilled in steel block, drilling spindle speed is $$600rpm$$, feed $$0.2$$$$mm/rev,$$ 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 constant $$C$$ will be

One brand of milling machine has the following two index plates supplied along with the indexing head:
Plate 1: $$15, 16, 17, 18, 19, 20$$ hole circles.
Plate 2: $$21, 23, 27, 29, 31, 33$$ hole circles.

It is proposed to mill a spur gear of $$28$$ teeth using simple indexing method. Which one of the following combinations of index plate and number of revolutions is correct?

Match List - $${\rm I}$$ (Milling problem) with List - $${\rm I}$$$${\rm I}$$ (Probable causes) and select the correct answer using the codes given below the lists:

Match List - $${\rm I}$$ (Cutting tools) with List - $${\rm I}$$$${\rm I}$$ (Features) and select the correct answer using the codes given below the lists:

A job of the shape shown in the figure below is to be machined on a lathe. The tool best suited for machining of this job must have

A non standard thread of pitch $$3.175$$ $$mm$$ is to be cut on a lathe having lead screw of pitch $$6$$ $$mm.$$ A change gear set provided 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 $$\left( {a/b\,\,x\,\,c/d} \right)$$ for machining the given thread are (assuming that the transmission ratio of the rest of the kinematic train between the lathe spindle and lead screw is equal to

A $$\phi $$ $$20$$ $$mm$$ through hole is to be drilled in a $$30$$ $$mm$$ thick plate using a double fluted, $${120^ \circ }$$ lip angle drill. The drill tip is at a distance of $$3$$ $$mm$$ from the plate surface when cutting is started and an over travel of $$2$$ $$mm$$ is recommended as a margin to ensure drilling through the full thickness of the plate. If the drill rotates at $$500$$ $$rev/min$$ and the feed per tooth is $$0.01$$ $$mm,$$ the machining time of the operation (in sec) will be

Consider the following statements:

The helical flute in a twist drill provides the necessary
$$1.$$ Clearance angle for the cutting edge.
$$2.$$ Rake angle for the cutting edge.
$$3.$$ Space for the chip to come out during drilling.
$$4.$$ Guidance for the drill to enter into the work piece.

Which of the statements given above are correct?

Match list - $${\rm I}$$ (machine tool) with list - $${\rm I}$$$${\rm I}$$ (machine tool part)

Match the mechanism with Machine

The purpose of helical grooves in a twist drill is to
$$1.$$ Improve the stiffness
$$2.$$ Save a tool material
$$3.$$ Provide space for chip removal
$$4.$$ Provide rake angle for the cutting edge

Select the correct answer suing the codes given below

A side and face cutter $$125mm$$ diameter has $$10$$ teeth. It operates at a cutting speed of $$14m/min$$ with a table traverse $$100mm/min.$$ The feed per tooth of the cutter is

A $$31.8MM$$ $$HSS$$ drill is used to drill a hole in cast iron block $$100$$ $$mm$$ thick at cutting speed of $$n20m/min$$ and feed $$0.3min/rev.$$ If the over travel of drill is $$4mm$$ and approach $$9mm,$$ the time required to drill hole is

Match GROUP - I with GROUP - II

A work-piece of $$2000$$ $$mm$$ length and $$300$$ $$mm$$ width was machined by a planning operation with the feed set at $$0.3$$ $$mm/stroke.$$ If the machine tool executes $$10$$ double strokes/min, the planning time for a single pass will be

Find the speed range ratio for the drilling machine spindle if the minimum and maximum diameters of drills used are $$5$$ $$mm$$ and $$25$$ $$mm$$ respectively and if the machinability indices for the work materials are $$120$$ (brass) and $$40$$ (alloy steel)

If the index crank of a dividing head is turned through one complete revoluation and $$10$$ holes in a $$30$$ hole circle plate, the work piece turns through (in degrees)

A drilling machine has to be designed with $$8$$ spindle speeds ranging approximately between $$120$$ to $$1200$$ $$rpm.$$ The $${5^{th}}$$ spindle speed is

The base of a brass bracket has to be rough ground to remove the unevenness. The $$4$$ wheels available in the store. The appropriate wheel is

A milling cutter having $$8$$ teeth is rotating at $$100$$ $$rpm.$$ The work piece feed is set at $$40mm/min$$. The feed per tooth is

The diameter and rotational speed of a job are $$100mm$$ and $$500$$ $$rpm$$ respectively. The high spots (chatter marks) are found at a spacing of $$30$$ $$deg$$ on the job surface. The chatter frequency is

For cutting double start screw threads of pitch $$2.0$$ $$mm$$ on a lathe, the thread cutting tool should have a feed rate of

Match the following

If the number of double strokes per minute in a shaper is calculated by ($$0.643\, \times \,$$ Cutting speed in $$mm/min$$) / length of the stroke in $$m,$$ then the return speed is faster than the cutting speed by