An abrasive article including a disc including a central axis; a primary outer edge substantially coaxial with the central axis and having a circumferential length, L.sub.1; a secondary outer edge substantially coaxial with the central axis and coplanar with the primary outer edge, the secondary outer edge having a circumferential length, L.sub.2, wherein L.sub.2 is less than L.sub.1; and a structurally weakened portion extending substantially adjacent to the secondary outer edge. In an embodiment, the abrasive article further includes a shedable portion configured to rupture the structurally weakened portion when the shedable portion is removed from the abrasive disc. In another aspect, an abrasive article having an initial outer circumferential length, L.sub.I, and a length of deliberately exposable circumferential edge surface, L.sub.OE, wherein L.sub.OE is greater than L.sub.I.

A structural unit, in particular a grinding wheel has a hole pattern for sucking away swarf from a machining surface. The hole pattern has at least three recesses which are arranged essentially along a first spiral line. The hole pattern also has at least three further recesses which are arranged essentially along a second spiral line which intersects the first spiral line in a region of at least one recess.

A structural unit, in particular a grinding wheel has a hole pattern for sucking away swarf from a machining surface. The hole pattern has at least three recesses which are arranged essentially along a first spiral line. The hole pattern also has at least three further recesses which are arranged essentially along a second spiral line which intersects the first spiral line in a region of at least one recess.

A grinder having a motor, wherein the grinder can be connected to a grinding disk. The grinder is configured to enable a wobbling movement, in addition to a grinding movement in a flat plane, of the grinding disk when the grinding disk is connected to the grinder. As a result, the grinder is able to perform a grinding movement, which constitutes a superimposition of a grinding movement in a flat plane and a wobbling movement of the grinding disk. This makes it possible to operate the grinder in two operating modes, the wobbling movement being able to be stopped by an arresting device. method for operating a grinder and a grinding disk for the grinder, the grinding disk having an unbalance for assisting the wobbling movement is also provided.

A grinder having a motor, wherein the grinder can be connected to a grinding disk. The grinder is configured to enable a wobbling movement, in addition to a grinding movement in a flat plane, of the grinding disk when the grinding disk is connected to the grinder. As a result, the grinder is able to perform a grinding movement, which constitutes a superimposition of a grinding movement in a flat plane and a wobbling movement of the grinding disk. This makes it possible to operate the grinder in two operating modes, the wobbling movement being able to be stopped by an arresting device. method for operating a grinder and a grinding disk for the grinder, the grinding disk having an unbalance for assisting the wobbling movement is also provided.

Methods and systems are provided for design and manufacture of a non-metallic polishing tool capable of polishing different surfaces and achieving a smooth and shiny finish. The polishing tool comprises an abrasive coated base surface, and a plurality of engravings in the base surface, forming cylindrical pillars. The pillars are arranged in concentric circular patterns to provide uniform polish and shine on a target material.

Methods and systems are provided for design and manufacture of a non-metallic polishing tool capable of polishing different surfaces and achieving a smooth and shiny finish. The polishing tool comprises an abrasive coated base surface, and a plurality of engravings in the base surface, forming cylindrical pillars. The pillars are arranged in concentric circular patterns to provide uniform polish and shine on a target material.

A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc's working face is planar; the second grinding disc's surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller's cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

The invention concerns a tool for machining of materials, specifically a grinding tool, which has a substantially rotationally symmetrical shape with respect to a rotation axis (R), the tool comprising an outer shell centered about the rotation axis and defining an internal space therein, wherein at least a part of a surface of the outer shell is provided with an abrasive coating or component, wherein the outer shell encases an internal skeleton structure in the internal space, the internal skeleton being integral with the outer shell and defining void volumes in the internal space thereby establishing material and void volumes of the internal space, and wherein the material to void ratio M/V is distributed substantially identically along each radius (r) centered around the rotation axis (R) and its corresponding symmetrical radius (r). The invention also concerns a method for producing such tool.

The invention concerns a tool for machining of materials, specifically a grinding tool, which has a substantially rotationally symmetrical shape with respect to a rotation axis (R), the tool comprising an outer shell centered about the rotation axis and defining an internal space therein, wherein at least a part of a surface of the outer shell is provided with an abrasive coating or component, wherein the outer shell encases an internal skeleton structure in the internal space, the internal skeleton being integral with the outer shell and defining void volumes in the internal space thereby establishing material and void volumes of the internal space, and wherein the material to void ratio M/V is distributed substantially identically along each radius (r) centered around the rotation axis (R) and its corresponding symmetrical radius (r). The invention also concerns a method for producing such tool.