A grinding apparatus has a spindle, a first wheel mount fixed to the lower end of the spindle, and a first grinding wheel mounted on the first wheel mount. The first grinding wheel has a first base and first abrasive members arranged annularly along the outer circumference of the first base in the form of a ring. A second wheel mount inside the first wheel mount is vertically movable. A second grinding wheel is mounted on the second wheel mount in concentric relationship with the first grinding wheel. The second grinding wheel includes a second base having an outer diameter smaller than the inner diameter of the ring formed by the first abrasive members. A plurality of second abrasive members are arranged annularly along the outer circumference of the second base in the form of a ring. The second wheel mount moves forward and away from a chuck table.

An elongate shaped abrasive particle comprises an elongate shaped ceramic body having opposed first and second ends joined to each other by at least two longitudinal sidewalls. At least one of the at least two longitudinal sidewalls is concave along its length. At least one of the first and second ends is a fractured surface. Methods of making elongate shaped abrasive particles and abrasive articles including them are also disclosed.

An elongate shaped abrasive particle comprises an elongate shaped ceramic body having opposed first and second ends joined to each other by at least two longitudinal sidewalls. At least one of the at least two longitudinal sidewalls is concave along its length. At least one of the first and second ends is a fractured surface. Methods of making elongate shaped abrasive particles and abrasive articles including them are also disclosed.

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 centred 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) centred around the rotation axis (R) and its corresponding symmetrical radius (r′). The invention also concerns a method for producing such tool.

There are provided: a linear motion guide device, which enhances workability of raceway surfaces and is capable of reducing production cost; and a production method for the linear motion guide device. For this purpose, a linear motion guide device includes a guide rail (1), a slider (2), and a plurality of rolling elements (4), and the guide rail (1) and the slider (2) individually have raceway surfaces (11, 21), which form a rolling path (3) of the rolling elements (4), at positions opposite to each other. Then, the rolling elements (4) are disposed in the rolling path (3), and the slider (2) moves with respect to the guide rail (1) via the rolling elements (4). The raceway surface (21) of at least one of the slider (2) and the guide rail (1) is composed of: a first raceway surface (21A); and second raceway surfaces (21B) extending on both sides of the first raceway surface (21), and surface roughness of the second raceway surfaces (21B) is set rougher than surface roughness of the first raceway surface (21A).

A silicon carbide single crystal substrate includes a first main surface, a second main surface, and a circumferential edge portion. The second main surface is opposite to the first main surface. The circumferential edge portion connects the first main surface and the second main surface. The circumferential edge portion has a linear orientation flat portion, a first arc portion having a first radius, and a second arc portion connecting the orientation flat portion and the first arc portion and having a second radius smaller than the first radius, when viewed along a direction perpendicular to the first main surface.

A method of processing a wafer having a first surface and a second surface opposite the first surface is provided. The method includes the steps of: holding the second surface of the wafer such that the first surface thereof is exposed; processing an exposed first surface side of an outer circumferential edge portion of the wafer with a processing tool including a grinding stone made of abrasive grains bound together by a bonding material, thereby forming on the outer circumferential edge portion a slanted surface that is inclined to the first surface so as to be progressively closer to the second surface in a direction from a central area of the wafer toward an outer circumferential edge thereof; and coating the first surface of the wafer with a liquid material according to a spin coating process, thereby forming a resist film on the first surface of the wafer.

An abrasive article can include a substrate, abrasive particles coupled by a bond material to the substrate, and a coating overlying at least partially the exterior surface of the bond material. The coating can be a poly(p-xylylene) polymer applied via vapor deposition and may provide enhanced strength to the bond material and extended life time to the abrasive article.

A method of manufacturing a grinding wheel includes a surface unevenness forming step of applying ultrasonic vibrations from an ultrasonic vibration applying unit through water to an annular slot defined in a surface of an annular base along circumferential directions thereof, thereby forming surface unevennesses on either one or both of a side surface and a bottom surface of the annular slot, and, after the surface unevenness forming step, a grindstone fixing step of fixing a plurality of grindstones to the annular slot with an adhesive.

A method of manufacturing a grinding wheel includes a surface unevenness forming step of applying ultrasonic vibrations from an ultrasonic vibration applying unit through water to an annular slot defined in a surface of an annular base along circumferential directions thereof, thereby forming surface unevennesses on either one or both of a side surface and a bottom surface of the annular slot, and, after the surface unevenness forming step, a grindstone fixing step of fixing a plurality of grindstones to the annular slot with an adhesive.