An abrasive article including a substrate; and an abrasive layer overlying the substrate, where the abrasive layer includes a blend of abrasive particles including a first type of abrasive particle comprising a polycrystalline material and having a first average friability F.sub.1, and a second type of abrasive particle comprising a polycrystalline material and having a second average friability, F.sub.2, where the blend comprises an average friability difference, ?F=|F.sub.1?F.sub.2|, within a range of at least 0.5% to not greater than 80%.

An abrasive article comprising a substrate having an elongated body and abrasive particles attached to the elongated body, the content of the abrasive particles oscillates along the length of the body between a minimum and maximum value, and the minimum content is greater than 0.

An abrasive article includes a substrate having an elongated body, a plurality of discrete tacking regions defining a discontinuous distribution of features overlying the substrate, where at least one discrete tacking region of the plurality of discrete tacking regions includes a metal material having a melting temperature not greater than 450? C., a plurality of discrete formations overlying the substrate and spaced apart from the plurality of discrete tacking regions, and a bonding layer overlying the substrate, plurality of discrete tacking regions, and plurality of discrete formations.

An abrasive article including a substrate; and an abrasive layer overlying the substrate, where the abrasive layer includes a blend of abrasive particles including a first type of abrasive particle comprising a polycrystalline material and having a first average friability F.sub.1, and a second type of abrasive particle comprising a polycrystalline material and having a second average friability, F.sub.2, where the blend comprises an average friability difference, ?F=|F.sub.1?F.sub.2|, within a range of at least 0.5% to not greater than 80%.

A super-abrasive grinding wheel includes a core and a super-abrasive grain layer provided on a surface of the core, the super-abrasive grain layer including diamond abrasive grains and CBN abrasive grains, the diamond abrasive grains and the CBN abrasive grains being fixed to the core in a single layer by a binder.

A grinding tool includes a substrate having a surface provided with a plurality of openings, and a plurality of grinding studs. Each of the grinding studs includes a stud portion and an abrasive particle attached to each other, the stud portions being respectively attached into the openings, and the abrasive particles protruding outward from the surface, each of the abrasive particles having a pattern cut across a tip thereof to define multiple apexes adjacent to one another.

Provided are: an electroplated tool; a screw-shaped grindstone for grinding a gear; a method for manufacturing the electroplated tool; and a method for manufacturing the crew-shaped grindstone for grinding a gear. Said tool having a parent material, a plating layer that has a high-level portion and a low-level portion formed as strips on the parent material at different heights along the direction intersecting the processing direction, and electrodeposited abrasive grains exposed from the surface of the plating layer. The difference in height of the plating layer is preferably 50-100% of the average particle diameter of the abrasive grains, the width of the high-level portion of the plating layer is preferably 150-200% of the average particle diameter of the abrasive grains, and the width of the low-level portion of the plating layer is preferably 100-800% of the average particle diameter of the abrasive grains.

A composite machining tool includes a tool body with at least one cutting edge and at least one grinding region. The grinding region is located adjacent to the cutting edge such that there is a gap between the grinding region and the cutting edge and such that when the tool performs a machining action the cutting edge and the grinding region act together on a material surface.

An outer blade cutting wheel is provided comprising an annular thin disc base and a blade section of bonded abrasive grains on the periphery of the base. Provided that an imaginary range is delineated by two imaginary planes extending parallel to the planar surfaces of the base and tangent to widthwise side portions of the blade section and two imaginary circumferences defined about the rotational axis and extending tangent to inner and outer perimeters of the blade section, the blade section occupies 10-40% by volume of the imaginary range minus the region of the base, and the widthwise side portions of the blade section have a dented shape relative to the imaginary planes. The cutting wheel is capable of cutoff machining at a high feed speed while maintaining a high accuracy and a low cutting load.

An outer blade cutting wheel includes an annular thin disc base and a blade section of bonded abrasive grains formed on the periphery of the base. The blade section includes widthwise side portions each of which is provided with channels extending from an inner perimeter to an outer perimeter of the blade section. The cutting wheel is capable of cutoff machining at a high feed speed while maintaining a high accuracy and a low cutting load.