Polished blank

opticalfor lense

Core-drilled blanks are supplied with the closest oversized diameters core-drill tool at least 0.080 greater than the diameter required by the customer. Core-drilled blanks have no bevels, edge chips will not exceed 0.030, and thickness is held to +/-0.010. Surface Finishes II-VI Infrared offers the following surface finishes on ZnSe, ZnS, and ZnS MS blanks. Core-drilled blanks may contain any of the standard surface finishes unless otherwise specified. As Generated (AG) -- Machined with a 220 grit wheel; produces a dull fine ground finish with generator marks still visible as viewed by the unaided eye. Requires additional grinding prior to further processing for an optical finish. Fine Ground (FG) -- Mechanically lapped using a 15µm aluminum oxide slurry; a dull fine-ground finish free of scratches as viewed by the unaided eye. View Polished (VP) -- Multi-stage mechanically polished with a transparent finish as viewed by the unaided eye; requires further processing for an optical finish. Used for inspection of internal quality cosmetics to guarantee the visual quality of the material. Note: All ZnSe and ZnS MultiSpectral materials have been view polished to inspect internal quality, regardless of surface finish.