FAQ

AA - Laboratory Grade
Used in constant temperature gaging rooms and metrology laboratories.

A - Inspection Grade
Used for general use in quality controlled inspection rooms.

B - Tool Room Grade
Used for shop work and production checking.

Why use granite as opposed to steel or aluminum?

Granite will react to changes in temperature about 1/2 as much as steel, and about 1/4 as much as aluminum.
Granite will deflect under load about 1/8 as much as steel, and about 1/20 as much as aluminum.
Granite is HARD. Equivalent to around 80 Rockwell C.
Granite is non-conductive, and by itself is non corrosive.
Granite can be finished to tighter flatness tolerances more quickly than steel or aluminum.
Weight per cubic foot:
- Granite (185 lbs.)
- Aluminum (168 lbs.)
- Steel (490 lbs.)
Electrical conductivity (Silver=100)
- Granite (0.0)
- Aluminum (63.0)
- Steel (12.0)