Drilling & reaming

Drilling & reaming Process

1. Mechanical Engineering Mechanical Engineering
Technology.Technology.
Topic: Drilling.Topic: Drilling.
WELCOMEWELCOME

2. Topic: Drilling.Topic: Drilling.
Objectives: Students should be able to:Objectives: Students should be able to:
1. State the definition for drilling1. State the definition for drilling
2.identify the parts of the drilling machine.2.identify the parts of the drilling machine.
3. identify three types of drilling Machines3. identify three types of drilling Machines
4. State at least five (5) safety precautions 4. State at least five (5) safety precautions
that are associated with the drilling that are associated with the drilling
machine. machine.
Mechanical Engineering Mechanical Engineering
Technology.Technology.

3. Drilling machines, also called drill
presses, cut holes in metal with a twist
drill. They also use a variety of other
cutting tools to perform the following
basic hole-machining operations: (1)
reaming, (2) boring, (3) counter-boring,
(4) countersinking, and (5) tapping
internal threads with the use of a
tapping attachment
DrillingDrilling

4. Drilling is the process of cutting Drilling is the process of cutting
holes in metals by using a drilling holes in metals by using a drilling
machine.machine.
Drills are the tools used to cut Drills are the tools used to cut
away fine shavings of material as away fine shavings of material as
the drill advances in a rotational the drill advances in a rotational
motion through the material. motion through the material.
DrillingDrilling

5. BoringBoring
Boring.Boring. Boring always Boring always
involves the enlarging of involves the enlarging of
an existing hole, which an existing hole, which
may have been made by a may have been made by a
drill or may be the result of drill or may be the result of
a core in a casting. a core in a casting.

6. Pedestal Type
Drilling Machine

7. Drilling
Machines
Radial Drilling
Machine

8. CNC
Drilling
Machine

9. Parts of the Bench Drilling Parts of the Bench Drilling
MachineMachine

10. Drilling Machine.Drilling Machine.

11. DriveDrive
An electric motor provides the An electric motor provides the
drive through belt and pulley to the drive through belt and pulley to the
spindle. The range of speeds will spindle. The range of speeds will
vary with different sizes and makes vary with different sizes and makes
of machines from 4 to 10, a typical of machines from 4 to 10, a typical
speed range being 300 r.p.m. to speed range being 300 r.p.m. to
2000 r.p.m.2000 r.p.m.

12. The TableThe Table
Made of cast iron, may be circular Made of cast iron, may be circular
or rectangular in shape and is or rectangular in shape and is
provided with slots to allow for the provided with slots to allow for the
bolting down of the vice or bolting down of the vice or
workpiece. The table may be workpiece. The table may be
locked at any position on the locked at any position on the
column and is sometimes capable column and is sometimes capable
of being swung round and locked of being swung round and locked
at any desired angle.at any desired angle.

13. Precautions For Drilling.Precautions For Drilling.
Twist drill must be clamped in the Twist drill must be clamped in the
drill chuck tightly drill chuck tightly
The workpiece to be drilled must The workpiece to be drilled must
be firmly secured by vice, or be firmly secured by vice, or
clamps. clamps.
Drill guard must be closed before Drill guard must be closed before
switch on the machine. switch on the machine.

14. Precautions cont.Precautions cont.
Use the correct drilling speed and Use the correct drilling speed and
apply suitable drilling force It is apply suitable drilling force It is
advisable to release the drill advisable to release the drill
occasionally, lift the drill, and clear occasionally, lift the drill, and clear
the hole of cutting. the hole of cutting.
Apply cutting fluid in the cutting Apply cutting fluid in the cutting
except for drilling Cast iron. except for drilling Cast iron.
Take care, when the drill is nearly Take care, when the drill is nearly
penetrated through the workpiece. penetrated through the workpiece.

15. Twist Drill
The twist drill is made from The twist drill is made from
High Speed Steel, tempered to High Speed Steel, tempered to
give maximum hardness give maximum hardness
throughout the parallel cutting throughout the parallel cutting
portion. portion.

16. Twist Drill Twist Drill

17. Twist DrillsTwist Drills

18. FlutesFlutes
. Flutes are incorporated to . Flutes are incorporated to
carry away the chips of metal carry away the chips of metal
and the outside surface is and the outside surface is
relieved to produce a cutting relieved to produce a cutting
edge along the leading side of edge along the leading side of
each flute. each flute.

19. Drill Features Drill Features

20. The point of the drill is ground The point of the drill is ground
to an angle of 59 degrees to the to an angle of 59 degrees to the
centre line to give two equal centre line to give two equal
cutting edges, and each side is cutting edges, and each side is
ground back to give " relief " of ground back to give " relief " of
about 12 degrees to each about 12 degrees to each
cutting edge as shown in figure. cutting edge as shown in figure.
Drill Features Drill Features

21. It is very important that drill It is very important that drill
points are central and that points are central and that
the lip angles are equal and the lip angles are equal and
that the cutting edges are that the cutting edges are
unchipped and the clearance unchipped and the clearance
angle correct. angle correct.
Drill Features Drill Features

22. Cutting Speeds.
.
Material Cutting Speed
Mild steel 18 to 25
stainless steel 12 to18
aluminium Up to 300

23. Special Type of Drill Special Type of Drill
Counterbore DrillCounterbore Drill To form a To form a
flat, or cylindrical recess to flat, or cylindrical recess to
accommodate the head of the accommodate the head of the
bolt. It is also used to provide a bolt. It is also used to provide a
level base on the rough level base on the rough
surfaces for nuts and washers. surfaces for nuts and washers.

24. Counterbore DrillCounterbore Drill

25. Countersink Drill.Countersink Drill.
Countersink Drill To form a conical Countersink Drill To form a conical
shaped recess to enable a shaped recess to enable a
countersunk screw or bolt to fit countersunk screw or bolt to fit
flush with the surface of the work. flush with the surface of the work.

26. Reamers Reamers
Reamer is made of Reamer is made of
hardened High Carbon hardened High Carbon
Steel or High Speed Steel. Steel or High Speed Steel.
It is classified into hand It is classified into hand
reamer and machine reamer and machine
reamer. reamer.

27. Functions of reamerFunctions of reamer
Functions of reamer are Functions of reamer are
to control the diameter of a hole to control the diameter of a hole
to improve the internal surface to improve the internal surface
finish finish
to improve the roundness of the to improve the roundness of the
hole hole

28. Hand reamerHand reamer
Hand reamer has two types of Hand reamer has two types of
flutes: - straight and spiral flutes: - straight and spiral
flutes. The spiral flutes hand flutes. The spiral flutes hand
reamer has a left hand spiral reamer has a left hand spiral
flutes. The purpose of the flutes. The purpose of the
design is to prevent the reamer design is to prevent the reamer
"screw in" the hole. "screw in" the hole.

29. Hand reamerHand reamer

30. Machine reamerMachine reamer
Machine reamer has a Machine reamer has a
straight shank or taper shank straight shank or taper shank
(Morse taper). The taper (Morse taper). The taper
shank can fit directly into the shank can fit directly into the
spindle of a machine while spindle of a machine while
the straight shank is hold by the straight shank is hold by
the collet. the collet.

31. Machine reamerMachine reamer

32. Expanding Expanding
Reamer/Adjustable Reamer/Adjustable
Reamer.Reamer.
The cutting diameter can be The cutting diameter can be
slightly varied by adjusting an slightly varied by adjusting an
inner taper against the loss cutting inner taper against the loss cutting
blades as shown in figure. This blades as shown in figure. This
type is used primarily for repetitive type is used primarily for repetitive
work to maintain a consistent size work to maintain a consistent size
throughout. throughout.

33. Expanding Expanding
Reamer/Adjustable Reamer/Adjustable
ReamerReamer

34. DrillingDrilling