Metrology Division- GMT  is one of the leading manufacturers and suppliers of granite surface plates, granite straight edge, granite master square and trisquares in India. We also provide fabricated stand and other accessories for our surface plates. GMT is well known for its Reference equipment and Metrology equipment.

The price and weight of the granite table varies according to size and grade. For more information and product catalogue email us at webmaster@gmtmetrology.com

We also undertake calibration of GMT make granite surface plates.

GRANITE SURFACE PLATE – Granite surface plates are manufactured to precision standards using the finest quality black granite for measuring applications, layout marking work and lapping precision parts.

Lapped to accuracies as per the DIN 876 standards, IS 7327:1991, GMT's surface plates are offered in four grades: Laboratory Grade – 00, Inspection Grade – 0, Tool Room Grade – I and II.

These are also supplied for use as reference bases for Co-ordinate measuring machines. T-slots can be provided on request for clamping components.

ACCURACY:

Rigorous quality control inspection is carried out at all stages.Final inspection is carried out by a High Precision Computerised Electronic Level.

ACCURACY UNDER LOAD:

Granite Surface Plates are capable of supporting a total normal load of 25 kgs. per 0.1Sq.Mtr.

CERTIFICATE:

A certificate of accuracy is supplied with each plate as per standards specified.

TECHNICAL DATA:

Granite Surface Plates are manufactured in five grades.The Typical application of these five grades of plates is as under.

GRADE 00 as per DIN :876:84 is of laboratory grade.It is specified for precision measurement in gauge rooms and metrology laboratories.

GRADE 0 is of inspection grade.It is specified for general work in quality control.

GRADE 1 is of tool room grade.It is specified for production checking work through the shop.

GRADE 2 & 3 are intended for use in shops for general inspection.The choice of grade 2 & 3 will depend on the application needs of the customer.

MATERIAL:

Granite Surface Plates are made from select granite with uniform distribution of light and dark constituents.In such granite, the minerals are very evenly distributed resulting in a homogenous appearance.The following are the representative properties of our granites.

Texture                      :     Fine.

Specific Gravity           :     3.08.

Hardness                    :     Scleroscope over 90.

Moisture of absorption :     Nil.

FLATNESS TOLERANCE :

The flatness deviation of a local area of 250 mm. x 250 mm. of the working surface shall not exceed.

1.  3.0 μm for plates of Grade 00.
2.  3.5 μm for plates of Grade 0.
3.  7.0 μm for plates of Grade 1.
4.  15.0 μm for plates of Grade 2.
5.  30.0 μm for plates of Grade 3.

1. Granite has one of the lowest co-efficient of expansion amongst known materials.
2. Granite does not rust.
3. It may chip,but will not develop a burr.
4. It is easy to keep clean.  

GRANITE SURFACE PLATES STANDS:

These are fabricated of heavy angle iron and reinforced to ensure rigidity.The stands are designed to withstand the weight of the granite surface plates and are supplied with 3 levelling screws for levelling the granite surface plates.

OPTIONAL ACCESSORIES: 

Plates will be supplied with a suitable Rexine Cover to protect both the working surface and side faces of the plate at extra cost.

TO MEET SPECIAL REQUIREMENTS WE OFFER:

1. Bigger size Granite Surface Plates with extra thickness.
2. Granite Surface Plates with inserts with drilled and tapped holes.
3. Granite Straight Edges.
4. Granite Master Squares.
5. Granite Cubes.
6. Master cylinder made of hardened & Grounded Steel. 
   

ACCURACY:

Rigorous quality control inspection is carried out at all stages.Final inspection is carried out by a High Precision Computerised Electronic Level.

ACCURACY UNDER LOAD:

Granite Surface Plates are capable of supporting a total normal load of 25 kgs. per 0.1Sq.Mtr.

CERTIFICATE:

A certificate of accuracy is supplied with each plate as per standards specified.

TECHNICAL DATA:

Granite Surface Plates are manufactured in five grades.The Typical application of these five grades of plates is as under.

GRADE 00 as per DIN :876:84 is of laboratory grade.It is specified for precision measurement in gauge rooms and metrology laboratories.

GRADE 0 is of inspection grade.It is specified for general work in quality control.

GRADE 1 is of tool room grade.It is specified for production checking work through the shop.

GRADE 2 & 3 are intended for use in shops for general inspection.The choice of grade 2 & 3 will depend on the application needs of the customer.

MATERIAL:

Granite Surface Plates are made from select granite with uniform distribution of light and dark constituents.In such granite the minerals are very evenly distributed resulting in a homogenous appearance.The following are the representative properties of our granites.

Texture                      :     Fine.

Specific Gravity           :     3.08.

Hardness                    :     Scleroscope over 90.

Moisture of absorption :     Nil.

FLATNESS TOLERANCE :

The flatness deviation of a local area of 250 mm. x 250 mm. of the working surface shall not exceed.

1.    3.0 μm for plates of Grade 00.
2.    3.5 μm for plates of Grade 0.
3.    7.0 μm for plates of Grade 1.
4.  15.0 μm for plates of Grade 2.
5.  30.0 μm for plates of Grade 3.

ADVANTAGES:

1. Granite has one of the lowest co-efficient of expansion amongst known materials.
2. Granite does not rust.
3. It may chip,but will not develop a burr.
4. It is easy to keep clean. 

 GRANITE SURFACE PLATE STANDS:

These are fabricated of heavy angle iron and reinforced to ensure rigidity.The stands are designed to withstand the weight of the Granite Surface Plates and are supplied with three levelling screws for levelling Granite Surface Plates.

OPTIONAL ACCESSORIES :

Plate will be supplied with a suitable Rexine Cover to protect both the working surface and side faces of the plate at extra cost.

TO MEET SPECIAL REQUIREMENTS WE OFFER:

1. Bigger size Granite Surface Plates with extra thickness.
2. Granite Surface Plates with inserts with drilled and tapped holes.
3. Granite Straight Edges.
4. Granite Master Squares.
5. Granite Cubes.
6. Master Cylinder  made of hardened & Ground Steel.
   

Our Products

 Granite Surface Plate

 Granite Straight Edge

Granite Master Square

Granite Tri-Square

Master CylinderSpecial Granite Dimensional Reference Equipment