A surface device includes a rigid holder (11), an elastically compressible interface (12) connected to the rigid holder, a flexible pad (13) adapted to be applied onto the surface to be machined (30) and a flexible belt (14) applied against and partially covering the side surface (18) of the interface (12), an annular portion (21) of the side surface (18) of the interface (12) being free between the belt (14) and the holder (11).