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FACING

Facing is the machining of the end surfaces and shoulders of a workpiece. In

addition to squaring the ends of the work, facing provides a way to cut work tolength accurately. Generally, only light cuts are required since the work will have

been cut to approximate length or rough machined to the shoulder.

TURNING

Turning is the machining of excess stock from the periphery of the workpiece toreduce the diameter. In most lathe machining operations requiring removal of large

amounts of stock, a series of roughing cuts is taken to remove most of the excessstock Then a finishing cut is taken to accurately "size" the workpiece.

Boring

Boring is the machining of holes or any interior cylindrical surface. The piece to be

bored must have a drilled or cored hole, and the hole must be large enough to insert

the tool. The boring process merely enlarges the hole to the desired size or shape.The advantage of boring is that a true round hole is obtained, and two or more

holes of the same or different diameters may be bored at one setting, thus ensuringabsolute alignment of the axis of the holes.

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Lathe Operation

1) Facing: In this operation the work piece of held in the chuck and the facing tools

is fed from the centre of the work piece toward the other surface with the help of a

cross slide.

2) Plat turning: It is an operation of removing excess amount of materials from the

surface of the cylindrical in the chuck or between centers and longitudinal feed is

given to the tools either by hand or power.

3) Taper turning: It is an operation of producing of external conical surface on a

work piece. A small taper may be produced with the help of a chamfering tool.

4) Step Turning: It is an operation of producing various steps of different diameter

in the work piece. This operation is carried out in the similar ways as plain turning.

5) Drilling: It is an operation of making of hole in a work piece with the help of a

drill. In this operation the work piece is held in a chuck and the drill is held in the

tailstock.

6) Reaming: It is an operation of finishing the previously drilled hole. In this

operation the work is held in a tail stock and it is fed into the hole in the similar ways

as for drilling.

7) Threading: It is an operation of cutting helical grooves on the external

cylindrical surface of work piece. In this operation the work is held in a chuck or

between centers and the threading tools is fed longitudinally to the revolving work.

8) Knurling: It is an operation of providing knurled surface of the work piece. In

this operation a knurled tool is moved longitudinally to a revolving work piece

surface.

4 to 8 Shaper

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The shaper is a reciprocating type of machine tool used for producing small flat

surface with the help of single point tools reciprocating over the stationary work

piece.

Principal part of a shaper

1) Base: It is a heavy structure of cast iron which supports other part of a shaper.

2) Column: It is a body like structure made up of cast iron and mounted upon the

base.

3) Ram: It is a reciprocating member which reciprocate on the guide ways

provided above the column it carries a tool slide on its head and a mechanism for

adjustable the stroke length.

4) Tool Head: It is attached to the front position of the Ram with help of a nut and

a bolt.

5) Cross Roil: It is attached to the front vertical portion of the column. It is used

for elevating the table over the column in the upward direction.

Drilling Machine

The basic purpose of drilling machine is to drill cylindrical holes in the work piece

the holes are cut out of the material with the cutting tools which is known as drill.

Working Principle of Drilling Machine

Rotary Motion: The rotary motion is called as main motion or cutting motion. In

some cases this motion is given to work piece also.

Linear motion:Towards the fixed work piece the motion is called as feed and it

controls the thickness of the chip.

Drilling Operation:

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1) Drilling: It is an important of producing a circular hole in a work piece by facing

a drill against it.

2) Boring: It is an operation of enlarging a circular hole that has already been

drilled by a single point tool.

3) Tapping: It is an operation of producing internal threads in a hole by means of a

tool called tap.

Article By: Janardhan J. Ghatghumar