Description The HST 359 backing pad for self-fastening discs is equipped with a fine self-fastening backing that allows for the secure fastening of abrasive discs with a velour self-fastening backing. The abrasive disc is replaced by simply pulling off the old abrasive by hand. No tools required. The new abrasive disc needs to be positioned as centrally as possible to keep wobbling and any resulting vibrations at a minimum.