Stone Made Parallel Bar

A surface plate that can be used as a parallel base for precision measurement as it is subject to minimal secular change and does not rust.
[Features]
· Precision parallel bar made of granite.
· Advantages include minimal secular change and no rust.
· 4 surfaces are precision surfaces.
· 2 pieces per set.
[Applications]
· Can be used as a parallel table for measurement on precision stone surface plates.