1. A pad for supporting an abrasive disc by being fixed with the abrasive disc to a shaft of a grinder, the pad comprising:a supporting surface configured to contact and engage the abrasive disc at a vertex portion, wherein a cross-section of the supporting surface along the radial direction has a V-shaped profile such that, when the grinder is not being operated, the abrasive disc contacts the supporting surface only at the vertex portion and portions of the abrasive disc located radially outward from the vertex portion are separated from the pad,
in a radial direction, an outer edge of the supporting surface being located inward of an outer edge of the abrasive disc,
the supporting surface including a taper portion extending from the vertex portion to the outer edge of the supporting surface, wherein the taper portion is inclined away from the abrasive disc as the taper portion approaches the outer edge of the supporting surface, and
the abrasive disc being not fixed to the taper portion so as to be moveable relative thereto between a first position where the abrasive disc is separated from the taper portion and a second position where the abrasive disc contacts the taper portion.