Abrasives

Known since prehistoric times (the polished stone age), the abrasive properties of certain minerals were confined to sharpening and polishing work (weapons, tools, marble, precious stones) from antiquity until the second half of the 19th century. The sandstone grindstones used by remoaners and the polishing trays used by lapidaries are remnants of this era.

It wasn't until around 1850 that the first grinding wheels made from natural abrasives appeared: quartz, emery, agglomerated with shellac, magnesia or rubber; it took another quarter century for the industrial manufacture of ceramic-agglomerated grinding wheels to take off, and another quarter century for the two artificial abrasives still most widely used today - aluminum oxide and silicon carbide - to be produced in significant quantities.

Since the beginning of the 20th century, the advent of these manufactured abrasives (sometimes incorrectly referred to as "artificial" as opposed to natural) has enabled the production of mechanical parts with tight geometric tolerances and high surface finishes.

Last but not least, the development of two superabrasives, diamond and cubic boron lenitride, in the 1960s, has been one of the most important recent milestones in the evolution of abrasives, enabling parts to be machined economically and with the utmost precision in materials of very high hardness: ceramics, metal carbides, superalloys, sintered alumina, overcarburized steels, etc. This has led to a major expansion in their use.