A multi-abrasive tool is constituted by a support on which abrasive elements are present. Such abrasive elements are arranged in a manner so as to form one or more paths along which the successive abrasive elements have grain size sequentially increasing or decreasing by an arbitrary quantity when passing from on element to the next. Such principle gives rise to abrasive tools with different conformation both for polishing machines and for grindstones. For roto-orbital and planetary polishing machines, and optionally orbital, such support is circular and the grain sequence is circumferential, or radial, or in both directions. A first tool is constituted by contiguous (or non-contiguous) circular rings, that are differently abrasive. A second tool comprises differently abrasive elements arranged along the circular peripheral edge. A third tool comprises differently abrasive elements arranged along a spiral path of 360 starting from the edge. A fourth tool comprises two 180 spiral paths with reversed roughness sequences. A fourth tool comprises pairs of differently abrasive small cylinders fixed to a plate on concentric circumferences. A fifth tool is obtained directly on the plate of the polishing machine by means of reliefs and spacers for fixing differently abrasive sectors. For linear polishing machines, the abrasive support is a belt along which differently abrasive rectangular or oblique zones follow each other. For alternative polishing machines, the abrasive support is a plate shaped like the aforesaid belt. For tools to use with grindstones, the multi-abrasive element has a cylindrical rotation symmetry, or conical with rounded tip, or spherical symmetry.

A multi-abrasive tool is constituted by a support on which abrasive elements are present. Such abrasive elements are arranged in a manner so as to form one or more paths along which the successive abrasive elements have grain size sequentially increasing or decreasing by an arbitrary quantity when passing from on element to the next. Such principle gives rise to abrasive tools with different conformation both for polishing machines and for grindstones. For roto-orbital and planetary polishing machines, and optionally orbital, such support is circular and the grain sequence is circumferential, or radial, or in both directions. A first tool is constituted by contiguous (or non-contiguous) circular rings, that are differently abrasive. A second tool comprises differently abrasive elements arranged along the circular peripheral edge. A third tool comprises differently abrasive elements arranged along a spiral path of 360 starting from the edge. A fourth tool comprises two 180 spiral paths with reversed roughness sequences. A fourth tool comprises pairs of differently abrasive small cylinders fixed to a plate on concentric circumferences. A fifth tool is obtained directly on the plate of the polishing machine by means of reliefs and spacers for fixing differently abrasive sectors. For linear polishing machines, the abrasive support is a belt along which differently abrasive rectangular or oblique zones follow each other. For alternative polishing machines, the abrasive support is a plate shaped like the aforesaid belt. For tools to use with grindstones, the multi-abrasive element has a cylindrical rotation symmetry, or conical with rounded tip, or spherical symmetry.

A grinding disc includes an inner layer (20) which is made of grindable material (containing abrasive particles) and an outer layer (20) which covers at least a portion of the surface of the inner layer (50) and which is made of non-grindable material (i.e. not-containing abrasive grain).

An abrasive article has an abrasive portion with an organic bond and abrasive particles. The abrasive article has a non-abrasive portion (NAP) mounted to the abrasive portion. The NAP includes molding compound (MC) having chopped strand fibers (CSF). The CSF can be coated with a thermoplastic coating having a loss on ignition (LOI) of at least about 2.4 wt %, and the NAP having no abrasive particles. The NAP can include an MC having no abrasive particles with a MOHS scale hardness of at least about 9. The NAP may include CSF coated with a primary coating and a secondary coating on the primary coating. The NAP may have an outer diameter that is at least half of but not greater than an outer diameter of the abrasive article.

An abrasive article has an abrasive portion with an organic bond and abrasive particles. The abrasive article has a non-abrasive portion (NAP) mounted to the abrasive portion. The NAP includes molding compound (MC) having chopped strand fibers (CSF). The CSF can be coated with a thermoplastic coating having a loss on ignition (LOI) of at least about 2.4 wt %, and the NAP having no abrasive particles. The NAP can include an MC having no abrasive particles with a MOHS scale hardness of at least about 9. The NAP may include CSF coated with a primary coating and a secondary coating on the primary coating. The NAP may have an outer diameter that is at least half of but not greater than an outer diameter of the abrasive article.

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.

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 grindstone corresponding to a rotatable grindstone or a stationary grindstone can be incorporated in a grinding device and is used for grinding raw materials. The grindstone includes a main body part and an outer circumferential ring part that can be detached from each other. The main body part has a coarse grinding part in which coarse grinding grooves corresponding to first coarse grinding grooves and second coarse grinding grooves for initially grinding the raw materials are formed. The outer circumferential ring part has a fine grinding part corresponding to a wall part in which fine grinding grooves for further grinding the raw materials ground by the coarse grinding part are formed. When the main body part and the outer circumferential ring part are assembled, the fine grinding part corresponding to the wall part is located at an outer circumference of the coarse grinding part.