Abstract: A tool for the roughing and/or polishing of hard surfaces such as stone, marble or the like, is described. The tool is usable in association with hand-operated machines, such as an angle grinder or the like, for manual treatment of surfaces by an operator. In particular, the tool provides a roughing and/or polishing tool whose flexibility and safety level is extremely high.

Abstract: An apparatus for grinding edges of rigid materials including a support member, an upper grinding element rotatably mounted relative to the support member, a bearing affixed to the upper grinding element, a lower grinding element rotatably mounted relative to the support member, and an insert element removably affixed around the bearing and interposed between the support member and one of the upper and lower grinding elements. The insert element is of an annular configuration and has an outer diameter less than an outermost diameter of the grinding elements. The insert element is interchangeable with various other insert elements.