surface finish

1. PRESENTATION ON
SURFACE FINISHING
PRESENTED BY :
• BHANU PRATAP SINGH
• ROLL NO.-1214340052
• BRANCH-M.E.-1(THIRD
YEAR)
SUBMITTED TO :
• MR. DEEPAK SHARMA

2. OBJECTIVE
• THIS PRESENTATION AIMS TO
PROVIDE A PIECE OF
KNOWLEDGE ABOUT SURFACE
FINISING AND DIFFERENT TYPES
OF SURFACE FINISHING
PROCESSES SUCH AS HONING,
LAPPING AND SUPER FINISHING

3. CONTENTS
• SURFACE FINISHING
• COMMON METHODS OF SURFACE FINISHING
• HONING
• LAPPING
• SUPER FINISHING

4. Surface finishing
Surface finishing may be defined as any process
that alters the surface of a material for asthetic and
functional purposes
It improve appearance and sales value of product
Used to resist wear, electrolytic decomposition,
and corrosive wear
Treatment process (chemical or electrical)
produces oxide of original metal on surface

5. Common methods for surface
finishing process
• Honing
• Lapping
• Polishing
• Super finishing

6. HONING
• Honing is an abrasive machining process that produces a
precision surface on a metal workpiece by scrubbing
an abrasive stone against it along a controlled path. Honing is
primarily used to improve the geometric form of a surface, but
may also improve the surface texture.
The surface of a honed workpiece

7. • Honing is a controlled, slow velocity,stock removal
process that uses fine abrasive stones to remove very
small amount of material.
• The process is used to size and finish drilled
holes,remove errors etc.
How honing process is done
• The honing stone usually are held in a honing head, with
stone being held against the work with controlled light
pressure.
• The honing tool is guided by the predrilled cavity.
• The stones are given complex motion to prevent single
grit from repeating

8. • For external and flat surfaces varying oscillatory
motions are given.
Honing is used in
• Gear teeth
• Valve seating
• Roller bearing etc.
Super abrasives and hone head for cylinders

9. Honing tools
• Honing uses a special tool, called a honing stone or a hone,
to achieve a precision surface.
• The hone is composed of abrasive grains that are bound
together with an adhesive.
• Generally, honing grains are irregularly shaped and about
10 to 50 micrometers in diameter
• Any abrasive material may be used
to create a honing stone, but the
most commonly used
are corundum, silicon carbide
, cubic boron nitride, or diamond.

10. Some commonly used honing tools

11. Some processes showing honing

12. Types of honing machines
• There are two types of honing machines that are
commonly used. They are as follows:
1. Horizontal honing machine
2. Vertical honing machine
• The classification is done on the basis of the motion
of the workpiece and tool.
• If machine carry a horizontal spindle and workpiece is
mounted on a table that can reciprocate to and fro
then the honing process is called horizontal honing
and if tool is mounted in a vertical spindle and moves
up and down then it is called vertical honing process.

13. Vertical honing machine
Horizontal honing machine

14. Advantages and disadvantages of
honing
Advantages
• Highly accurate holes are
produced.
• Very little heat is generated.
• Tolerances can be easily
maintained.
• Surface finish produced is
very smooth.
• Hole of any dimensions can
be honed.
• High productivity at low
cost can be obtained.
Disadvantages
• Impossible to improve lack
of straightness in holes.
• Difficult to hone tough non
ferrous metals due to
clogging of the pores of
abrasive.
• Amount of stock removal is
less.

15. Lapping
• Lapping is a machining process, in which two surfaces
are rubbed together with an abrasive between them, by
hand movement or by way of a machine.

16. • Lapping is an ancient machining technique
• It is a precision process or combination of processes
used to provide flatness , parallelism, size and surface
finishes to extremely demanding tolerances.
How lapping is done
• First the workpiece is held in pressure plate onwhich
pressure is to be applied.
• There is a rotating wheel on which a coating of
abrasive material is present.
• Now workpiece and abrasive material are brought in
contact by applying pressure on pressure plate and
due to thes contact the material is removed.

17. Lapping is used in
• Gauges
• Piston pins
• Valves
• Gears
• Thrust washers
• Optical parts

18. Lapping tools
• Two types of tools are used on the basis of abrasive
material
• Abrasives like, jeweller's rouge, optician's
rouge, emery, silicon carbide, diamond, etc. are used.
• For machine lapping the preferred lap material is cast iron
• Soft steel, bronze, brass and lead are used in manual
lapping.

19. Some common lapping tools

20. Some processes showing lapping

21. Types of lapping
Lapping is done by following methods
1. Hand lapping
2. Machine lapping
• Hand lapping is done by using hand held tools for
both flat and external cylinder work
• Machine lapping is done to obtain highly finished
surface on many articles such as worm and worm
gears, camshafts, automobile engine parts etc.

22. Types of lapping machine
There are five types of lapping machines and
they are discussed below:
1. Vertical lapping machine
2. Flat machine lapping
3. Centreless roll lapping machine
4. Centreless lapping machine
5. Lapping spherical surfaces

23. Advantages and disadvantages of
lapping
Advantages
• Extreme accuracy in both
tolerances and geometry.
• Fast stock removal.
• No clamping or heat
distortion.
• No expensive tooling
required.
• Very thin and non magnetic
parts can be processed.
• Irregular shaped parts can
be easily processed.
Disadvantages
• Since lapping is a finishing
operation, parts should not
be far from the expected
size and geometry before
lapping.
• Reside of compound left on
the part after lapping must
be removed
• Trail and error still may be
needed to get the optimum
results.

24. Super finishing process
• Super finishing is a
surface improving
process that removes
the undesirable
fragmentation metal,
leaving a base of solid
crystalline metal
• It differ form honing in
then motion given to
the stone.

25. Types of super finishing
• It is of two types:
1. Cylindrical super finishing
2. Flat super finishing
• In cylindrical super finishing a bonded form abrasive stone
having a width of about two third of diameter of part to be
finished and the same length is operated at low speed and
pressure.
• The motion given to the stone is oscillating with an amplitude
of 1.6 to 64 mm at about 450 cycles.
• The work is rotated at the speed of0.25m/s.
• In flat super finishing flat surface may be super finished.
• The upper spindle is spring loaded quill on which stone is
mounted
• The lower spindle carries the work.
• Both spindles are parallel so that when they rotate the result is
a flat smooth surface

26. Cylindrical super finishing
Flat super finishing

27. Super finishing tools
• The tools used are
basically stones which has
a specified kind of
abrasive, size type of
bond and hardness.
• These stones are
mounted on special
attachments.
• The machine used have
the capability to hold
stones in adjustable and
interchangeable holders.

28. Advantages and disadvantages of
super finishing
Advantages
• Produce excellent surface
finish in a minimum time.
• Type of surface finish may
be preselected.
• Process is easy adapted to
high volume productions .
Disadvantages
• Super finishing cannot be
used to correct feature
location such as
concentricity.

29. Super finishing is used in
• Automobile component such as gudgeon pins.
• Aircraft components.
• Heavy earth moving equipments.