1 Jun
2015
1 Jun
'15
17:35
On 06/01/2015 08:15 PM, Per Jessen wrote: > diamond-tipped bits - believe the stuff used is called "Crushing Boart" [ not that expensive ] { - as wikipedia says : "Bort or boart is a term used in the diamond industry to refer to shards of non-gem-grade/quality diamonds. In the manufacturing and heavy industries, "bort" is used to describe dark, imperfectly formed/crystallized diamonds of varying levels of opacity. The lowest grade, "crushing bort", is crushed by steel mortars and used to make industrial-grade abrasive grits. Small bort crystals are used in drill bits. The Democratic Republic of the Congo provides 75% of the world supply of crushing bort" } ............ regards -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org