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)
Last Updated Thursday, December 27 2007 @ 02:47 AM EST; 439 Hits 
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