Parallel Set of Optical Flats:
1 1/4" Diameter, 1/2" Thick, Parallel to .000004"
Van Keuren's optical flats use only the most carefully selected annealed clear fused quartz. Fused quartz possesses a very low coefficient of linear expansion and is resistant to abrasion. All Van Keuren Optical Flats come furnished in a fitted case with a certificate of calibration stating the actual flatness directly traceable to the National Institute of Standards & Technology.
Flats in optical parallel sets differ in thickness by approximately 0.0125", providing a parallelism check at two splindle positions, each one-half turn apart. For metric micrometers, the difference is 0.25 mm.
Optical Flats are the easiest and best way to test the flatness of a flat lapped or polished surface. Such surfaces are found on micrometers, measuring machines, gage blocks, snap gages, ring seals, valve seats and precision flat lapped parts.
Micro-coating is available by request and is applied to the flat to help clarify the image.
Reconditioned Optical Flats:
Do you have worn or scratched optical flats? They can be resurfaced to any desired accuracy, single or double surface, and will be indistinguishable from new flats. Reworked flats will be certified, showing traceability to the N.I.S.T. with the test number and date. Please call for an estimate.