Sand hardwoods and concrete with the BlueFire® H831 ZA medium grit paper H&L floor sanding disc, which boasts a self-sharpening zirconia alumina abrasive for fast cuts. The BlueFire® H831 outperforms comparable discs, thanks to the combination of a tough ZA abrasive and a tear-resistant E-weight paper backing. The open coat and anti-static design cut down on dust and loading for improved performance. Faint sanding marks produce a good finish and a hook and loop back enables fast and easy disc changing.