Archived posting to the Leica Users Group, 2002/03/24
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]How much is a tonne of Leica glass? Well 10,000 metric tonne really. Which is 10,000,000 kilograms Per Schott Glass Product Specification: N-LAK34 runs 4.02 g/cm3 or about 4000 kilograms per cubic metre (LAK34 is just the first optical glass product sheet I found and this stuff is really heavy compared to ordinary glass!) So 10,000,000 kilograms would be 2,500 cubic metre of glass.or 74,818 cubic feet. That's a pile 10 by 10 by 25, or 10 ft by 10 ft by 748 feet high. That's a lot of glass, a lot of lens elements. Wasteage in production has been mentioned. It seems unlikely that a significant number of production melts would be unusable. It is the nature of manufacturing processes to put in place procedures which will result in high yields. I do believe there is a significant amount of glass "consumed" in the production of a lens element. Cutting shaping and grinding from a blank to the final element have to remove material. I don't know how much but if only 25% of the material ends up in the element our pile is still mighty big. At this point I wonder if 10,000 metric tons mentioned in Leicaview is an accurate transcription or translation of the interview with Norbert Meinert. Perhaps someone knows a way to verify. Or maybe I made an error in calculation. ;-) - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html