Black Granite Surface Plates



Granite Surface Plates meet IS.7327 - 1991 for flatness. Granite surface Plates are manufactured to precision standards using the highest quality granite.

Accuracy : Rigourous quality control inspection is carried out 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 0.1. Sq. mtr.

Certificate : A certificate of accuracy is supplied with each plate as per IS: 7327 - 1991.

Technical Data : Granite Surface Plates are manufactured in Four Grades. The typical applicaton of these four grades of plates are as under :

  • GRADE 00 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 is for use in shops for general inspection.


Material : Granite Surface Plates are made from seiect granite with uniform distribution of light and dark constituents. In such granite the minerals are evenly distributed resulting in a homogenous appearance. The following are the representative Properties of our Granites.

Flatness Tolerance :
The flatness deviation of a local area of 250 mm X 250 mm of the working surface shall not exceed :

  • 3.5 µm for plates of Grade 00
  • 7 µm for plates of Grade 0
  • 15 µm for plates of Grade 1
  • 30 µm for plates of Grade 2


Advantages :

  • Granite has one of the lowest cu - Efficients of expansion amongst known materials :
  • Granite does not rust.
  • It may chip, but will not develop a burr.
  • 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 3 levelling screws for leveling the granite surface plates. To meet special requirements, we offer bigger size of Granite surface plate with extra thickness, Comparator stands, Granite straight edges, Granite master squares and master cylinder. Detail on these products will be forwarded on request.