National Stock Number
5210-01-092-9859
National Stock Number (NSN) 5210-01-092-9859, or NIIN 010929859, (optical flat) was assigned April 8, 1980 in the Federal Logistics Information System (FLIS). NIIN 010929859 was cancelled on December 15, 2017, with a cancelled status of "Item is Cancelled - Inactive." There is no known replacement specified for this stock number. This NSN does not replace any other NSNs.
There are 2 manufacturer part numbers associated with this NSN. One of those part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by 2 suppliers. Today, one supplier is listed as an Active supplier for this NSN. Of the active suppliers, only one supplier is deemed design controlled or valid supply parts.
This part number has not been procured by the US Government in over 5 years.
This NSN is assigned to Item Name Code (INC) 18274. [A FLAT, TRANSPARENT PIECE OF GLASS, GENERALLY OF FUSED QUARTZ, WITH ONE OR BOTH PRINCIPAL SURFACES POLISHED TO WITHIN A FEW MILLIONTHS OF AN INCH OF A TRUE PLANE. IT IS USED IN CONJUNCTION WITH A MONOCHROMATIC LIGHT SOURCE TO MEASURE THE FLATNESS OF PRECISION FINISHED SURFACES, AND TO DETERMINE THE DISTANCE AND PARALLELISM BETWEEN PRECISION FINISHED SURFACES BY COMPARISON WITH KNOWN STANDARDS. IN OPERATION THE FLAT IS SUPERIMPOSED, REFERENCE SURFACE DOWNWARD, ON THE PARTS UNDER TEST AND WHEN ILLUMINATED BY MONOCHROMATIC LIGHT THE RAYS REFLECTED FROM THE REFERENCE SURFACE ARE EITHER REINFORCED OR NEUTRALIZED BY THE RAYS REFLECTED FROM THE SURFACE UNDER TEST PRODUCING INTERFERENCE BANDS WHICH REVEAL ANY VARIATIONS IN THE THICKNESS OF THE FILM OF AIR BETWEEN SURFACE UNDER TEST AND THE FLAT. EXCLUDES:OPTICAL PARALLELS.]. There is no data in the HMIRS and the NSN is in an FSC not generally suspected of containing hazardous materials. NSN 5210010929859 contains an unknown precious metal.
This information was last updated on Aug 01, 2025.