Very sharp and long lasting to help you form your curve fast and accurately.
You can rely on India Astronomy Club - IAC optical grade abrasives because they are accurately graded to ensure that no larger, scratch producing sizes or foreign materials are present. Further, special processing steps are used to produce abrasive grains of like shape and edge for longer and more economical grinding action. There are many different ways to designate abrasive sizes. We uses two — Grit and Micron sizing. A one micron size abrasive particle measures one millionth of a meter. Silicon Carbide Very sharp and long lasting to help you form your curve fast and accurately.
Silicon carbide is an extremely sharp, synthetic abrasive which approaches the diamond in hardness. It is made by mixing finely ground petroleum coke with pure glass sand. The mixture is loaded into a crucible and heated by electric arc to temperatures in excess of 2000°C. The intense heat of the arc causes the carbon in the coke and the silicon in the sand to fuse into silicon carbide. By varying the speed of the heating and cooling cycle the final crystal size is determined. A long, slow cooling cycle allows a few crystals to grow to a very large size while quick cooling forms numerous small crystals. The cooled mass is then broken up and rough graded by screening. The individual crystals are treated by impact, crushing or air blasting to remove brittle edges. Finally, it is graded by screening, water sedimentation, hydraulic flotation or air classification, with the latter used for the very fine grades.
Because of its extreme hardness, silicon carbide is ideal for grinding Pyrex, which is harder than ordinary glass, or very deep curve generation used for refractor, Maksutov, or richest field objectives. The very coarse sizes (40 and 60) are used for diameters larger than six inches or deep curves where a large amount of glass must be removed.
India Astronomy Club - IAC silicon carbide is the very best optical grade available. Every step during the manufacture and packaging is controlled to ensure the high purity and scratch free qualities sought by the precision optical worker. Accurately graded sizes from 40 to 500 grit are stocked. We recommend this abrasive for use on Pyrex up to the final critical lapping stages
