MIDLAND METROLOGY LTD GRANITE PRODUCTS

What are Granite Plates and Tables and why are they used? To undertake any method of accurate measurement we need a firm and flat base from which to work. Imagine decorating a room at home without a strong wallpaper table. Much the same applies whether you are using micrometers or height gauges.

Every manufacturing company, who are also measuring must be able to work from a flat base. This base can be metal (cast iron or steel) or granite. Why are there two different types of table? The reason is that both metal and granite surfaces have distinct advantages, over each other

Granite is less porous than steel, so therefore absorbs less moisture. This results in the reduced amount of rust being created. It is more stable than steel. Rigidity is the criterion.

Granite has been compressed over 500 million years to create this stability.
It is much harder wearing and has a more consistent hardness surface than steel.
Granite is on the Mohs scale of Hardness along with diamond which is the hardest mineral. When damaged by dropping sharp items, the result is a small indent, and not a burr that would affect flatness so accurate measurement is achieved.

The only disadvantage is that it is non magnetic, and sometimes it is convenient to use magnetic tools. However, overall granite is a far superior surface from which to work.
These plates and tables come in a very wide range of sizes. 300 mm x 300 mm is usually the smallest kept in stock, up to
2500 mm x 1200 mm generally being the largest stocked.

Recently we received an order for two large tables from an American company. These tables are 3600mm x 2200 mm. The weight is in excess of 9 tons. Also within the family range of Granite Products are Precision Engineers Squares, Parallels, V Blocks and Cubes. A full price list appears on Midland Metrology web Pages.