GMT started manufacturing lapping & polishing machine in 1971. It was built for in-house use and until then hand lapping process was used for finishing surface plates. Critical parts for our workholding devices required a finishing and buffing machine. There was demand in the market for valve lapping and lapping plates. Since GMT had a captive ferrous foundry, castings for lap plate and lapping machine were easier to source.
Since then GMT has become one of India's largest lapping machine manufacturers and suppliers with over 350 installations throughout India mainly to the valve and pump industry. When a buyer in Japan wanted a super finishing machine for lapping large granite plates, GMT designed and supplied a 3000mm dia flat lapping machine.
Pump manufacturers, electronic industries, valve manufacturers, etc., have found a sure way of obtaining positive sealing.
2. What is Lapping?
Lapping is a mechanical precision finishing operation
done to achieve high dimensional accuracy
Diagram of the lapping process in action
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An ISO 9001:2008 & EMS 14001 Company
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3. What is Lapping?
It helps achieve positive sealing by obtaining
high degree of flatness and surface finish
A typical example would be
lapping automotive pump
seals
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4. The Lapping Process
Lapping improves surface finish by
reducing peaks & valleys on a surface
Surface finish of 0.2 µ Ra achievable with
GMT Lapping machines
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5. Advantages of Lapping
Accessible flat surfaces of parts of any shape & size and any type of
material can be lapped
Improves service life of the moving parts which are subject to wear
Improves geometrical & dimensional accuracies
Absolutely no distortion in the component after
lapping since no clamping devices are used
The lapping process generates minimal heat so hardened
parts will not have to be hardened again
Reduction of peaks and valleys results in maximum bearing area
between mating surfaces - This ensures tight seating of seals
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6. Typical Applications & Industries that
Make Use of Lapping
Valve Manufacturers
Air Compressor Industries
Automotive industries
Pump Manufacturers
Electronic Industries
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7. Carbon
What Can be Lapped?
A wide variety materials, hard or soft can be lapped.
A partial list includes:
Cast Iron
Tungsten Plastics
Ceramics
Stainless Steel
Bronze
Silicon
(Eg.wafer)
Rubber
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8. GMT manufactures flat lapping
machines both
single side & double side
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An ISO 9001:2008 & EMS 14001 Company
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9. Single Side Lapping Machine
Consists of a rigid rotating
spindle with a lapping plate,
and three or four conditioning
rings
GMT’s single side lapping
machines provide flatness to a
precision of one light band
(0.0003mm) on 75mm
diameter with a surface finish
of 0.2 µRA
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10. GMT has supplied lapping machines to
over 300 customers all over India
Sizes range from 300mm to 3000mm diameter
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12. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
300mm - 400mm
diameter
Model 06-01, 06-02
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13. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
610mm diameter
Model 06-13
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14. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
900mm diameter
Model 06-03
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15. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
1200mm diameter
Model 06-05
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16. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
1500mm diameter
Model 06-06
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17. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
1800mm diameter
Model 06-07
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18. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
2100mm diameter
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An ISO 9001:2008 & EMS 14001 Company
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19. Range of Lapping Machines Manufactured by GMT
Single side lapping machines
3000mm diameter
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20. Range of Lapping Machines Manufactured by GMT
Double side lapping machines/Planetary lapping machines
Model 24-01
To maintain:
•Flatness
•Surface finish
•Parallelism
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21. Range of Lapping Machines Manufactured by GMT
Double side lapping machines/Planetary lapping machines
Model 24-02 with
pneumatic
lifting arrangement
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An ISO 9001:2008 & EMS 14001 Company
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22. Range of Lapping Machines Manufactured by GMT
Double side lapping machines/Planetary lapping machines
Model 24-11
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23. Range of Lapping Machines Manufactured by GMT
Double side lapping machines/Planetary lapping machines
Model 24-11
with 4 way lapping
(rotating top & bottom lap plates)
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24. Accessories
Hand lap plate
To correct minor
imperfections and for
small batches
Cupboard
To store polishing paper,
pad, hand tools etc,
(can be used as a machine
stand for 300 and 400mm
diameter bench model lapping
machines)
Straight Edge
To check the flatness
of lap plate
Monochromatic Light & Optical Flat
Used for measuring the
flatness.
Sodium Vapour Lamp
used with a wavelength
of 0.00058 mm
Polishing Stand
Fitted with 4/0 emery paper
to achieve reflective surface
after lapping for light band
interpretation
(for flatness checking)
4/0 Emery Paper
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25. Measuring Flatness
Unit for flatness measurement is half the wavelength
i.e. λ / 2 = 0.000589 / 2 = 0. 0002945mm
(rounded off to 0.0003mm i.e. 0.3 micrometer)
Monochromatic Lamp
Optical Flat
Flatness is measured using
GMT make Monochromatic lamp
& Optical flat
The GMT Monochromatic lamp unit
provides light source with sodium
vapour lamp.
The wave length of Sodium light in air (λ air):
0. 000589mm i.e. 0. 589 micrometer)
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26. Measuring Flatness
An imaginary tangent intersects
one interference band immediately
above it
Imaginary tangent line
This shows the flatness to be
below one band or 0.0003mm
Point of contact
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27. Measuring Flatness
Optical flat is in contact with the
surface being tested, usually where
pressure is applied causing the air
film to be squeezed thin at that
place
When light is reflected from the
surface under test, interference
occurs and is visible as a
pattern of light & dark bands
The width of each band = λ / 2
( (i.e.) 0.0003 micrometer)
Point of contact or line of contact
Point of contact
Straight, parallel and equally
spaced bands show that surface is
perfectly flat within 0.0003mm
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28. GMT also offers optional features like:
• Water cooling for lap plate,
• Variable speed drive,
• Pneumatic lift arrangement,
• Lapping fluid recycling
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Accessories for Lapping
29. Guindy Machine Tools Limited
www.gmt.co.in
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Editor's Notes
The Lapping Process
What is Lapping?
Lapping is a low pressure abrading process of rubbing together two surfaces with a lapping medium, such as lapping fluid and lapping Grit, between them.
Lapping is the first mechanical precision finishing tooling operation done to achieve high dimensional accuracy. This improves the geometrical accurateness, provides a fine surface finish, and, ensures a close fit between mating parts.
The benefits of lapping are many.
Lapping improves surface finish by eliminating the peaks and valleys, as can be seen from these graphs of before lapping and after lapping process.
The benefits of lapping are many.
Lapping improves surface finish by eliminating the peaks and valleys, as can be seen from these graphs of before lapping and after lapping process.
Reduction of peaks and valleys results in maximum bearing area between mating surfaces. This ensures tight seating of seals.
This improves the service life of moving parts, which are subject to wear and tear.
Lapping improves geometrical and dimensional accuracies, and, there is absolutely no distortion in the component after lapping since no clamping devices are used.
The lapping process minimizes the necessity of re-hardening hardened parts because of less heat generation. Accessible flat surfaces of parts from any shape & size to any type of material can be lapped.
Any unskilled operator can work on the machine.
A simple carrier plate design is enough to accommodate the component for lapping , thus, a complicated fixture is not required.
Typical Applications and industries that make use of Lapping include: Valve Manufacturers, air compressor industries, automotive industries, pump manufacturers, and, electronic industries.
Any material, hard or soft, can be lapped.
Materials that lend themselves to lapping include: Cast iron, Tungsten, Plastic, Ceramics, Stainless steel alumina, Silicon, Bronze, Rubber, and, all non ferrous materials & alloys
The range of lapping machines manufactured at GMT include the Single side precision lapping machines for Flat Lapping and the Double side planetary lapping machines
The range of lapping machines manufactured at GMT include the Single side precision lapping machines for Flat Lapping and the Double side planetary lapping machines
The range of lapping machines manufactured at GMT include the Single side precision lapping machines for Flat Lapping and the Double side planetary lapping machines
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
The single sided lapping machine consists of a rigid rotating spindle with a Lapping plate and three or four conditioning rings. GMT’s single side lapping machines provide flatness to a precision of one light band, 0.0003 mm, on 100 diameter with less than 0.2 micron surface finish.
Models include:
The 300 and 400 Diameter, 610 diameter, 900 diameter, 1200 diameter, 1500 diameter, 1800 diameter, 2100 diameter, and, the 3000 diameter models.
Accessories that make up the lapping machine units include:Hand lap plate, cupboard machine stand for housing 300 & 400 diameter lapping machines, straight edge, abrasive pump, optical flat, monochromatic light and polishing stand.
Contact Guindy Machine Tools Limited for all your lapping needs.
Thank You