On 03/29/2014 03:39 AM, Jeshua Lacock wrote: > > > > My 1080 pound 4x5 foot granite surface has a glass cut looking surface that I > bought surplus. > Anyways, do you think the reason it is shiny is because it is grade A, while > the grade B should be matte? > > It is most likely an optical bench, made to be extremely stable and free of vibration, and probably had air bellows supporting it. It is probably NOT a surface plate, ie. one that is ground with diamond paste to be flat to within some insane tolerance for inspection purposes. The fact it has a mirror finish means it was polished, not lapped against other plates, in the time-honored 3-plate method of automatic generation of flats.
Jon ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
