MACHINE TOOLS

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MODULE II
SHAPER MACHINE
SHAPER MACHINE
SHAPER MACHINE
 SHAPER MACHINE
● The shaper is a machine tool used primarily for:
○ Producing a flat or plane surface which may be in a horizontal, a vertical or an
angular plane.
○ Making slots, grooves and key ways
○ Producing contour of concave/convex or a combination of these

Video explanation
 SHAPER MACHINE
CONSTRUCTION DETAILS (VIDEO EXPLANATION)
Base
● It is the main body of the machine. It consist all element of machine. It works as
pillar for other parts. Base is made by cast iron which can take all compressive
loads.
Ram
● It is the main part of the shaper machine. It holds the tool and provides the
reciprocating motion to it.
● It is made by cast iron and move over ways on column. It is attached by the
rocker arm which provide it motion in crank driven machine and if the machine is
hydraulic driven it is attached by hydraulic housing.
 SHAPER MACHINE
CONATRUCTION DETAILS
Ram
 SHAPER MACHINE
CONSTRUCTION DETAILS
Tool head
● It is situated at the front of the ram. Its main function is to hold the cutting tool.
The tool can be adjusted on it by some of clamps.
Table
● It is the metal body attached over the frame. Its main function is to hold the
work piece and vice over it. It has two T slots which used to clamp vice and work
piece over it.
 SHAPER MACHINE
CONSTRUCTION DETAILS
Column
● Column is attached to the base. It provides the housing for the crank slider
mechanism. The slide ways are attached upper section of column which provide
path for ram motion
Cross ways
● It consist vertical and horizontal table sideways which allow the motion of table.
It is attach with some cross movement mechanism
 SHAPER MACHINE
CONATRUCTION DETAILS
Clapper box
● It carries the tool holder. The
main function of clapper box is
to provide clearance for tool in
return stock. It prevents the
cutting edge dragging the work
piece while return stock and
prevent tool wear..
 SHAPER MACHINE
CONSTRUCTION DETAILS
Stroke adjuster
● It is attached below the table. It is used to control the stroke length which
further controls the ram movement
Table support
● These are attached front side of the table and used to support the weight of
table during working
TYPES OF OPERATIONS
 SHAPER MACHINE
TYPES OF OPERATIONS PERFORMED IN A SHAPER
○ Machining horizontal surface.
○ Machining vertical surface.
○ Machining angular surface.
○ Cutting slots, grooves and keyways.
○ Machining irregular surface.
○ Machining splines or cutting gear.

VIDEO EXPLANATION
 SHAPER MACHINE
TYPES OF OPERATIONS PERFORMED IN A SHAPER
 SHAPER MACHINE
TYPES OF OPERATIONS PERFORMED IN A SHAPER
 SHAPER MACHINE
TYPES OF OPERATIONS PERFORMED IN A SHAPER
 SHAPER MACHINE
TYPES OF OPERATIONS PERFORMED IN A SHAPER
 SHAPER MACHINE
TYPES OF OPERATIONS PERFORMED IN A SHAPER
Cutting slots, grooves and keyways.
 SHAPER MACHINE
TYPES OF SHAPER
● Shapers can classified into many types based on several criteria:
1. Based on the type of driving mechanism used
○ Crank and slotted lever driving mechanism type
○ Whitworth quick return driving mechanism type
○ Hydraulic driving mechanism type
2. Based on the table design
○ Plain Shaper
○ Universal Shaper
 SHAPER MACHINE
TYPES OF SHAPER
3. Based on the position of the reciprocating ram used
○ Horizontal shaping machine (Most common type of shaper used)
○ Vertical shaping machine
○ Travelling head shaping machine
4. Based on the type of cutting stroke of the tool
○ Push out type
○ Draw cut type
QUICK RETURN MECHANISM
 SHAPER MACHINE
QUICK RETURN MECHANISM
● A quick return mechanism is an system to produce a reciprocating effect such
that time taken by system in return stroke is less time taken by it in the forward
stroke.
● In quick return mechanism, a circular motion is converted into reciprocating
motion just like crank and lever mechanism but it has return stroke time is
different from forward stroke time.
● This mechanism is used in many machines. Some of them are shaper machines,
slotter machines, screw press, mechanical actuator etc. With the help of quick
return mechanism, the time needed to cutting is minimized
 SHAPER MACHINE
QUICK RETURN MECHANISM

TYPES (Video explanation)

1. crank and slotted lever mechanism

2. Whithworth mechanism
3. Hydraulic mechanism
4. automatic feed mechanism
 SHAPER MACHINE
1. Crank and slotted lever mechanism (Video)
 SHAPER MACHINE
QUICK RETURN MECHANISM
1. Crank and slotted lever mechanism
● In crank and slotted link mechanism. The power is transmitted to the bull gear by
a pinion which receives its power from an individual motor.
● In a two gear system, the smaller gear is called pinion and the larger gear is
called bull gear.
● The radial slide is bolted to the centre of the bull gear. This radial slide carries a
sliding block into which the crank pin is fitted.
● As the bull gear will rotate, the crank will revolve at uniform speed.
 SHAPER MACHINE
QUICK RETURN MECHANISM
1. Crank and slotted lever mechanism
● The sliding block which is mounted upon the crank pin is fitted upon the crank
pin is fitted within the slotted link. This slotted link is pivoted upon at its bottom
end attached to the frame of column. The upper end of the sliding link is
bifurcated and attached to the ram block by a pin.
● When the bull gear rotates, the crank pin revolves at a uniform speed. The
sliding block fastened to the crank pin will rotate on the crank pin circle and at
the same time this slider will slide up and down in the sliding link
 SHAPER MACHINE
QUICK RETURN MECHANISM
1. Crank and slotted lever mechanism
● As the slider will move inside the sliding link, it will provide a rocking movement
to the sliding link and this movement will be transferred to the ram providing it a
reciprocatory motion.
● Hence the rotary motion of the bull gear is converted into reciprocatory motion
of ram.
 SHAPER MACHINE
QUICK RETURN MECHANISM
2. Whithworth mechanism
 SHAPER MACHINE
QUICK RETURN MECHANISM
2. Whithworth mechanism
● This mechanism changes the rotary motion to oscillatory motion like the crank
and lever mechanism.
● The difference between the crank and lever mechanism and Whitworth
mechanism is that in Whithworth mechanism the return stroke is faster than the
forward stroke while in the crank and lever mechanism the forward stroke is of
same speed as that of return stroke.
 SHAPER MACHINE
QUICK RETURN MECHANISM
2. Whithworth mechanism
● Parts used in Whitworth mechanism
1) Slotted Bar.
2) Slider
3) Crank – It will rotate
 SHAPER MACHINE
QUICK RETURN MECHANISM
2. Whithworth mechanism
● Whitworth quick return mechanism is the second inversion of slider crank
mechanism in which the crank is fixed.
● In this mechanism, the Slider in slotted bar is connected to the crank. When the
crank rotates, the slider will slide inside the slotter bar and the slotted bar will
oscillate. As the slotted bar oscillate, the ram will move in forward and backward
direction.
● The return stroke or ideal is faster than the forward stroke in this mechanism.
 SHAPER MACHINE
QUICK RETURN MECHANISM
2. Whithworth mechanism
● In the above figure AP is the slotted bar and link 1, CD is link 2, AC which is crank is link
3 and link 4 is the slider.
● In this mechanism the link CD i.e link 2 forming the turning pair is fixed as shown in the
figure above.
● The crank AC revolves with uniform velocity with its centre at A.
● A sliding block attached to the crank pin at B slides along the slotted bar AP and thus
causes Ap to oscillate
● about the pivoted pint A. A short link PR transmits the motion from AP to the ram
which carries the tool and
● thus forward stroke and backward stroke is obtained.
 SHAPER MACHINE
QUICK RETURN MECHANISM
2. Whithworth mechanism
● The crank needs to rotate through an angle of ( β ) for the forward stroke and it
needs to rotate through an angle
● of ( α ) for forward stroke.
● As crank moves with uniform angular velocity , time taken to cover angle α will
be less than the time taken to
● cover angle β. Hence time taken in return stroke will be less than time taken in
forward stroke. In this way, the quick return mechanism works.
 SHAPER MACHINE
QUICK RETURN MECHANISM
3. Hydraulic mechanism
 SHAPER MACHINE
QUICK RETURN MECHANISM
3. Hydraulic mechanism
● Hydraulic drive mechanism is one of the mechanism used in shaper machine. In
this mechanism, the ram is moved forward and backward by a piston moving in a
cylinder placed under the ram.
● This machine consists of a constant discharge oil pump, a cylinder , a valve
chamber and a piston. The piston rod is bolted to the ram body. Hydraulic fluid is
used in hydraulic quick return mechanism for the movement of ram.
 SHAPER MACHINE
QUICK RETURN MECHANISM
4. automatic feed mechanism
 SHAPER MACHINE
QUICK RETURN MECHANISM
4. automatic feed mechanism
● The automatic feed mechanism of the table is very simple. This is done by
rotating a ratchet wheel, mounted at the cross-feed screw. This enables a
corresponding equal rotation of the cross-feed screw after each stroke..
SPEED, FEED AND DEPTH OF CUT
 SHAPER MACHINE
Cutting Speed
● It is defined as the average linear speed of the tool during the cutting stroke in
m/min, which depends on number of ram strokes ( or ram cycles) per minute
and length of the stroke.
Feed
● Feed f is the relative motion of the work piece in a direction perpendicular to the
axis of the reciprocation of the arm. In shaper, feed is normally given to the work
piece and can be automatic or manual. It is expressed in mm/double stroke or
simply mm/stroke because no cutting is done in return stroke.
Depth of Cut
● Depth of cut d is the thickness of the material removed in one cut, in mm...
WORK HOLDING DEVICES
 SLOTTER MACHINE
WORK HOLDING DEVICES
● Vice
● T-Bolts and step block
● Angle plate
● Clamps and stop pins
● V- block
● Special Fixtures
SHAPER SPECIFICATION
 SHAPER MACHINE
SHAPER SPECIFICATION
● Length of Ram stroke: (457 mm)
● Range of Ram speeds: (12, 24, 40 & 72 strokes per minute)
● Working surface of table: (483 mm * 330 mm)
● Max Table Travel – Horizontal: (610 mm)
● Max Table Travel – Vertical: (457 mm)
● Angular movement of table on either side: (600)
● Maximum size of Tool Shank in Tool Head: (51m * 21mm)
● Maximum vertical travel of Tool Slide: (152 mm)
● Maximum swivel of Tool Head: (600)
● Main Drive Motor: (3 H.P./ 950 rpm).
SHAPER MACHINE
PLANER MACHINE
 PLANER MACHINE
● The planer or planing machine is a machine tool, which like the shaper produces
flat surfaces in horizontal, vertical or inclined plane.
● The fundamental difference is that the planer operates with an action opposite
to that of the shapers, i.e., the work piece reciprocates past one or more
stationary single point cutting tools.
● Planers are meant for machining large sized work pieces, which cannot be
machined by the shaping machines.
● The work table is moved back and forth on the bed beneath the cutting head
either by mechanical means , such as a rack and pinion gear or by a hydraulic
cylinder.
VIDEO EXPLANATION
PLANER MACHINE
PLANER MACHINE
PLANER MACHINE
PLANER MACHINE
PLANER MACHINE
PLANER SPECIFICATION
PLANER MACHINE
PLANER MACHINE
SLOTTER MACHINE
 SLOTTER MACHINE
● Slotting machine (slotter) is a reciprocating type of machine tool similar to a
shaper or a planer machine.
● It may be considered as a vertical shaper. The main difference between a slotter
and a shaper is the direction of the cutting action.
● The slotting machine operates in a manner similar to the shaper. However, the
cutting tool moves vertically direction rather than in a horizontal direction. The
work piece is held stationary.
● The slotting machine has a vertical ram and a hand or power operated rotary
table.
VIDEO EXPLANATION
SLOTTER MACHINE
SLOTTER MACHINE
SLOTTER MACHINE
 SLOTTER MACHINE
CONSTRUCTION DETAILS
Bed or case
● Bed or case is made up of cast iron. It supports column, tables, ram, driving
mechanism, etc. the top of the bed carries horizontal ways which the worktable
can transverse.
Cross-slide
● Cross-slide can be moved parallel to the face of the column. The circular
worktable is mounted on the top of the cross-slide.
Hand wheels
● Hand wheels are provided for rotating the table for the longitudinal and cross
traverse.
 SLOTTER MACHINE
CONSTRUCTION DETAILS
Column
● They are made up of cast iron and it houses the driving mechanism. The vertical front
face of the column is accurately finished for providing ways along which the ram moves
up and down.
Ram
● Ram is provided to reciprocate to and fro motion. At the bottom of the ram, it carries
the cutting tool. It is more massive and moves vertically, at a right angle to the
worktable, instead of having the horizontal motion of a shaper.
Table
● Table holds the workpiece and is adjustable in longitudinal and crosswise direction. The
table can be rotated about its center
 SLOTTER MACHINE
TYPES OF SLOTTER MACHINE

1. Puncher slotter
2. Precision slotter
3. Production slotter
4. Key slotter
 SLOTTER MACHINE
USES OF SLOTTER MACHINE
● Internal machining of blind hole
● Machining on internal section such as splines, keyways, various slots and
grooves, teeth
● Machining of die, punches, straight and curved slots
● Cutting of teeth on ratchet or gear rings which require primarily rotary feed
● By combining cross, longitudinal and rotary feed movements of the table, even
complex contours can be machined.
WORK HOLDING DEVICES
 SLOTTER MACHINE
WORK HOLDING DEVICES
● Vice
● T-Bolts and clamps
● Special Fixtures
SLOTTER TOOLS
 SLOTTER MACHINE
SLOTTER TOOLS
● Bit Tools
● Round nose tools for machining contoured surface
● Square nose tools for flat surfaces.
SLOTTER SPECIFICATION
 SLOTTER MACHINE
SPECIFICATION
● The maximum stroke length.
● Diameter of rotary table.
● Maximum travel of saddle and cross slide.
● Type of drive used.
● Power rating of motor.
● Net weight of machine.
● Number and amount of feeds
● Floor area required
SLOTTER MACHINE
DRILLING MACHINE
 DRILLING MACHINE
● Drilling is the operation of producing circular hole in the work-piece by using a
rotating cutter called DRILL.
● The machine used for drilling is called drilling machine.
● The drilling operation can also be accomplished in lathe, in which the drill is held
in tailstock and the work is held by the chuck.
● The most common drill used is the twist drill.
● Drilling machine is the simplest and accurate machine used in production shop.
● The work piece is held stationary ie. Clamped in position and the drill rotates to
make a hole.
DRILLING MACHINE (VIDEO)
 DRILLING MACHINE
TYPES (video explanation)
Based on construction
○ Portable drilling machine
○ Sensitive drilling machine
○ Radial drilling machine
○ Up-right drilling machine
○ Gang drilling machine
○ Multi-spindle drilling machine
Based on Feed
○ Hand driven drilling machine
○ Power driven drilling machine
 DRILLING MACHINE
1. SENSITIVE (OR) BENCH DRILLING MACHINE
 DRILLING MACHINE
1. SENSITIVE (OR) BENCH DRILLING MACHINE
● It is designed for drilling small holes at high speeds in light jobs. High speed and
hand feed are necessary for drilling small holes.
● The base of the machine is mounted either on a bench or on the floor by means
of bolts and nuts. It can handle drills up to 15.5mm of diameter. The drill is fed
into the work purely by hand.
● The operator can sense the progress of the drill into the work because of hand
feed. The machine is named so because of this reason.
● A sensitive drilling machine consists of a base, column, table, spindle, drill head
and the driving mechanism.
 DRILLING MACHINE
1. SENSITIVE (OR) BENCH DRILLING MACHINE
● Base: The base is made of cast iron and so can withstand vibrations. It may be mounted
on a bench or on the floor. It supports all the other parts of the machine on it.
● Column: The column stands vertically on the base at one end. It supports the work
table and the drill head. The drill head has drill spindle and the driving motor on either
side of the column.
● Table: The table is mounted on the vertical column and can be adjusted up and down
on it. The table has ‘T’-slots on it for holding the workpieces or to hold any other work
holding device. The table can be adjusted vertically to accommodate workpieces of
different heights and can be clamped at the required position. The table can also be
swung to any desired position.
 DRILLING MACHINE
1. SENSITIVE (OR) BENCH DRILLING MACHINE
● Drill spindle: An electric motor and the mechanism meant for driving the spindle
at different speeds are mounted on the top of the column. Power is transmitted
from the electric motor to the spindle through a flat belt or a ‘V’ belt.
● Drill head: Drill head is mounted on the top side of the column. The drill spindle
and the driving motor are connected by means of a V-belt and cone pulleys. The
motion is transmitted to the spindle from the motor by the belt. There is no
power feed arrangement in this machine. The pinion attached to the handle
meshes with the rack on the sleeve of the spindle for providing the drill the
required down feed. The spindle rotates at a speed ranging from 50 to 2000
r.p.m.
 DRILLING MACHINE
2. UP-RIGHT DRILLING MACHINE
 DRILLING MACHINE
2. UP-RIGHT DRILLING MACHINE
● The upright drilling machine is designed for handling medium sized workpieces.
Though it looks like a sensitive drilling machine, it is larger and heavier than a
sensitive drilling machine.
● Holes of diameter up-to 50mm can be made with this type of machine. Besides,
it is supplied with power feed arrangement.
● For drilling different types of work, the machine is provided with a number of
spindle speeds and feed.
● The main parts of a upright drilling machine are base, column, table and drill
head.
 DRILLING MACHINE
3. RADIAL DRILLING MACHINE
(VIDEO EXPLANATION)
 DRILLING MACHINE
3. RADIAL DRILLING MACHINE
● The radial drilling machine is intended for drilling on medium to large and heavy
workpieces.
● It has a heavy round column mounted on a large base.
● The column supports a radial arm, which can be raised or lowered to enable the
table to accommodate workpieces of different heights.
● The arm, which has the drill head on it, can be swung around to any position.
The drill head can be made to slide on the radial arm. The machine is named so
because of this reason.
● It consists of parts like base, column, radial arm, drill head and driving
mechanism
 DRILLING MACHINE
3. RADIAL DRILLING MACHINE
● Base: The base is a large rectangular casting and is mounted on the floor of the shop. Its top is
accurately finished to support a column at one end and the table at the other end. ‘T’-slots are
provided on it for clamping heavy workpieces.
● Column: The column is a cylindrical casting, which is mounted vertically at one end of the
base. It supports the radial arm and allows it to slide up and down on its face. The vertical
adjustment of the radial arm is effected by rotating a screw passing through a nut attached to
the arm. An electric motor is mounted on the top of the column for rotating the elevating
screw.
● Radial arm: The radial arm is mounted on the column parallel to the base and can be adjusted
vertically. The vertical front surface is accurately machined to provide guideways for the drill
head. The drill head can be adjusted along these guideways according to the location of the
work. In some machines, a separate motor is provided for this movement. The arm may be
swung around the column. It can also be moved up and down to suit workpieces of different
heights.
 DRILLING MACHINE
3. RADIAL DRILLING MACHINE
● Drill head: The drill head is mounted on the radial arm and houses all mechanism
for driving the drill at different speeds and at different feed. A motor is mounted
on top of the drill head for this purpose. To adjust the position of drill spindle
with respect to the work, the drill head may be made to slide on the guideways
of the arm. The drill head can be clamped in position after the spindle is properly
adjusted.
● Universal radial drilling machine: It is a machine in which the spindle can be
swivelled to any required angle in vertical and horizontal positions.
 DRILLING MACHINE
4. GANG DRILLING MACHINE
 DRILLING MACHINE
4. GANG DRILLING MACHINE
● Gang drilling machine has a long common table and a base. Four to six drillheads
are placed side by side. The drillheads have separate driving motors. This
machine is used for production work.
● A series of operations like drilling, reaming, counterboring and tapping may be
performed on the work by simply shifting the work from one position to the
other on the work table. Each spindle is set with different tools for different
operations.
 DRILLING MACHINE
5. Multiple Spindle Drilling Machine
● This machine is used for drilling a number of holes in a workpiece simultaneously
and for reproducing the same pattern of holes in a number of identical pieces.
● A multiple spindle drilling machine also has several spindles. A single motor
using a set of gears drives all the spindles. All the spindles holding the drills are
fed into the work at the same time.
● The distances between the spindles can be altered according to the locations
where holes are to be drilled. Drill jigs are used to guide the drills
WORK HOLDING DEVICES
 DRILLING MACHINE
WORK HOLDING DEVICES
● The work should be held firmly on the machine table before performing any operation
on it. As the drill exerts very high quantity of torque while rotating, the work should
not be held by hand. If the workpiece is not held by a proper holding device, it will start
rotating along with the tool causing injuries to the operator and damage to the
machine.
● The devices used for holding the work in a drilling machine are
○ Drill vise
○ ‘T’ - bolts and clamps
○ Step block
○ V - block
○ Angle plate
○ Drill jigs
 DRILLING MACHINE
WORK HOLDING DEVICES
 DRILLING MACHINE
WORK HOLDING DEVICES
TOOLS USED IN A DRILLING
MACHINE
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
● Different tools are used for performing different types of operations.
● The most commonly used tools in a drilling machine are
1. Drill
2. Reamer
3. Counter bore
4. Countersink
5. Tap
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
1. DRILL
● A drill is a tool used to originate a hole in a solid material. A helical groove known
as ‘flute’ is cut along the length of the drill.
● Different types of drills are
○ Flat Drill
○ Straight fluted drill
○ Twist drill
○ Centre drill
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
1. DRILL
● Twist drills are the type generally used in shop work. They are made of High
speed steel (HSS) or High carbon steel.
● There are two types of twist drills namely (i) Straight shank twist drill and
(ii)Taper shank twist drill.
● The diameter of the straight shank drill ranges from 2 to 16mm.
● Taper shanks is provided on drills of larger diameter.
 DRILLING MACHINE
TOOLS USED IN A
DRILLING MACHINE
1. DRILL: TWIST
DRILL
NOMENCLATURE

(Video explanation)
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
1. DRILL: TWIST DRILL NOMENCLATURE
Axis
● It is the longitudinal centre line of the drill running through the centres of the
tang and the chisel edge.
Body
● It is the part of the drill from its extreme point to the commencement of the
neck, if present. Otherwise, it is the part extending up to the commencement of
the shank. Helical grooves are cut on the body of the drill.
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
1. DRILL: TWIST DRILL NOMENCLATURE
Shank
● It is the part of the drill by which it is held and driven. It is found just above the
body of the drill. The shank may be straight or taper. The shank of the drill can
be fitted directly into the spindle or by a tool holding device.
Tang
● The flattened end of the taper shank is known as tang. It is meant to fit into a
slot in the spindle or socket. It ensures a positive drive of the drill.
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
1. DRILL: TWIST DRILL NOMENCLATURE
Neck
● It is the part of the drill, which is diametrically undercut between the body and
the shank of the drill. The size of the drill is marked on the neck.
Point
● It is the sharpened end of the drill. It is shaped to produce lips, faces, flanks and
chisel edge.
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
1. DRILL: TWIST DRILL NOMENCLATURE
Lip
● It is the edge formed by the intersection of flank and face. There are two lips and
both of them should be of equal length. Both lips should be at the same angle of
inclination with the axis (59°).
Land
● It is the cylindrically ground surface on the leading edges of the drill flutes
adjacent to the body clearance surface. The alignment of the drill is maintained
by the land. The hole is maintained straight and to the right size.
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
1. DRILL: TWIST DRILL NOMENCLATURE
Flutes
The grooves in the body of the drill are known as flutes. Flutes form the cutting
edges on the point. It allows the chips to escape and make them curl. It permits the
cutting fluid to reach the cutting edges
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
2. REAMER
● The tool used for enlarging and finishing a previously drilled hole is known as a
reamer. It is a multi tooth cutter and removes smaller amount of material. It
gives a better finish and accurate dimension
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
2. REAMER (more details)
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
3. COUNTER BORE
● A Counter bore is a multi tooth cutting tool used for enlarging the top of the previously
machined hole. It has three or four cutting teeth. The flutes on them may be straight or
helical. Straight fluted tools are used for machining softer materials like brass and
aluminium and for short depth of cut. Helical fluted counter bores are used for longer
holes.
4. COUNTER SINK
● A countersink has cutting edges on its conical surfaces. It has a similar construction of a
counter bore except for the angle of the cutting edges. The angle of countersinks will
generally be 60°, 82° or 90°. It is used for enlarging the top of the holes conically.
 DRILLING MACHINE
TOOLS USED IN A DRILLING MACHINE
5. TAP
● A tap has threads like a bolt. It has three to four flutes cut across the threads. It
can cut threads on the inside of a hole. The flutes on the threads form the
cutting edges. It is a multi point cutting tool. It will dig into the walls of the hole
as the lower part of the tap is slightly tapered. The shank of the tap is square
shaped to enable it to be held by a tap wrench.
TYPES OF OPERATIONS
 DRILLING MACHINE
DRILLING OPERATIONS
● (Video explanation)
● Though drilling is the primary operation performed in a drilling machine, a
number of similar operations are also performed on holes using different tools
● Operations that can be performed in a drilling machine are
○ Drilling
○ Reaming
○ Boring
○ Counter boring
○ Counter sinking
○ Tapping
 DRILLING MACHINE
DRILLING OPERATIONS
1. DRILLING
● It is an operation by which holes are produced in solid metal by means of
revolving tool called ‘Drill’.
 DRILLING MACHINE
DRILLING OPERATIONS
2. Reaming
● Reaming is accurate way of sizing and finishing the pre-existing hole. Multi tooth
cutting tool. Accuracy of ±0.005mm can be achieved
 DRILLING MACHINE
DRILLING OPERATIONS
3. Boring
● Boring is a process of enlarging an
existing hole by a single point cutting
tool. Boring operation is often preferred
because we can correct hole size, or
alignment and can produce smooth
finish. Boring tool is held in the boring bar
which has the shank. Accuracy of
±0.005mm can be achieved.
 DRILLING MACHINE
DRILLING OPERATIONS
4. Counter boring
● Internal turning operation for enlarging end of the hole
● This operation uses a pilot to guide the cutting action to accommodate the heads
of bolts.
● Counter boring tool is used
 DRILLING MACHINE
DRILLING OPERATIONS
5. Counter sinking
● Conical enlargement of the end of the
hole
● It is done by large size drill bit than
hole
● Cone angles of 60°, 82°, 90°, 100°,
110°, 120°
● Eg: Screw seating
 DRILLING MACHINE
DRILLING OPERATIONS
6. Tapping
● Tapping is the process by which
internal threads are formed. It is
performed either by hand or by
machine. Minor diameter of the
thread is drilled and then tapping is
done.
SPEED, FEED AND DEPTH OF CUT
 DRILLING MACHINE
Cutting Speed
● It’s the peripheral speed of the drill. The cutting speed depends upon the
properties of the material being drilled, drill material, drill diameter, rate of
speed, coolant used etc….
Feed
● It’s the movement of drill along the axis (rpm).
Depth of Cut
● The distance from the machined surface to the drill axis.
● As the depth of hole increases, the chip ejection becomes more difficult and the
fresh cutting fluid is not able to cutting zone. Hence for machining the lengthy
hole special type of drill called ‘gun drill’ is used
DRILLING MACHINE
SPECIFICATION
 DRILLING MACHINE
SIZE OF A DRILLING MACHINE (SPECIFICATION)
● The maximum diameter of the drill that it can handle
● The size of the largest workpiece that can be centred under the spindle
● Distance between the face of the column and the axis of the spindle
● Diameter of the table
● Maximum travel of the spindle
● Numbers and range of spindle speeds and feeds available
● Morse taper number of the drill spindle
● Floor space required
● Weight of the machine
● Power input is also needed to specify the machine completely
THE END