Concrete Grinding
Concrete can vary in properties a great deal. Hard concrete requires a segment with a softer bond than the standard type, to grind properly and avoid glazing. On the other hand soft concrete requires a hard bond to avoid excessive wear of the tools. Therefore, always check the wear of the segments after a while, to see that no abnormal wear occurs. If so, try if another type of tool works better, with this specific type of floor.
Before grinding starts, check the floor for bolts or other metallic obstacles and remove them, as they can destroy your segments completely.
As a preparation for a carpet or thicker coating, a coarser single stage grinding is normally adequate and there we have a number of different suggestions covering all type of concrete. For thin coating or paint, a follow up with a finer segment is required. Alternative segments are available for different concrete properties there too.
Finally, if you find an extremely hard concrete, causing glazing also with the correct tooling, try to wet the floor somewhat since damp concrete is much easier to grind.