Workpiece holder (3) for coupling a workpiece (2) provided with reference surfaces (30) to a machining device (200) for manufacturing a rotational-symmetrical tool (1) with at least one geometrically defined cutting edge (10), the workpiece holder (3) comprises a machine part (31) configured to be connectable to the machining device (200) in a releasable rotationally fixed manner, a clamping part (32) configured to receive and clamp the workpiece (2) in a releasable manner. The clamping part (32) of the workpiece holder (3) comprises at least one slot (40) provided at a circumference thereof and configured to provide access to the reference surfaces (30) of the clamped workpiece (2) therethrough.

A dual sided abrasive article is presented that includes a first side with a first abrading face and a second side, with a second abrading face. The second side is opposite the first side and separated by a thickness. The article also includes a center hole extending from the first side to the second side through the thickness. The article also includes a fastener for coupling the abrasive article to a powered tool, the fastener positioned within the center hole.

A dual sided abrasive article is presented that includes a first side with a first abrading face and a second side, with a second abrading face. The second side is opposite the first side and separated by a thickness. The article also includes a center hole extending from the first side to the second side through the thickness. The article also includes a fastener for coupling the abrasive article to a powered tool, the fastener positioned within the center hole.

An adjustable stroke mechanism has a housing with a central axis and a wall enclosing a cavity. At least one counterweight is movably disposed within the cavity. A mounting assembly is disposed within the cavity. The mounting assembly has a workpiece attachment mechanism. A stroke adjustor couples the at least one counterweight with the mounting assembly. The stroke adjustor enables the counterweight and mounting assembly to move with respect to one another such that a distance between the counterweight and the mounting assembly is variably adjusted which, in turn, variably adjusts a stroke radius of the workpiece attachment mechanism with respect to the central axis of the housing.

A sealing portion on a lower end of a cover portion of a spindle cover has an upper side surface and a lower side surface that are inclined toward an outer circumferential surface of a spindle. A larger-diameter disk and the outer circumferential surface of the spindle define therebetween a second gap that is narrower than a first gap defined between the spindle and the cover portion. The second gap is effective to prevent a processing waste liquid from entering between the spindle and the spindle cover to prevent a solid waste contained in the processing waste liquid from sticking to the spindle. The spindle is thus prevented from becoming less liable to rotate smoothly due to solid waste deposits.

A sealing portion on a lower end of a cover portion of a spindle cover has an upper side surface and a lower side surface that are inclined toward an outer circumferential surface of a spindle. A larger-diameter disk and the outer circumferential surface of the spindle define therebetween a second gap that is narrower than a first gap defined between the spindle and the cover portion. The second gap is effective to prevent a processing waste liquid from entering between the spindle and the spindle cover to prevent a solid waste contained in the processing waste liquid from sticking to the spindle. The spindle is thus prevented from becoming less liable to rotate smoothly due to solid waste deposits.

A processing apparatus includes a processing unit. The processing unit includes a spindle, a spindle housing having an air bearing for rotatably supporting the spindle by using air, and a tool mounted on the front end of the spindle. The spindle housing has an air supply passage for supplying air to the air bearing, an air supply port connected to the air supply passage, an air discharge passage, and an air discharge port. The air supply port is connected through an air supply line to an air source. The air supply line is provided with a pressure gauge and a flowmeter. A first allowable value is previously set for the pressure to be detected by the pressure gauge, and a second allowable value is previously set for the flow rate to be detected by the flowmeter.

A processing apparatus includes a processing unit. The processing unit includes a spindle, a spindle housing having an air bearing for rotatably supporting the spindle by using air, and a tool mounted on the front end of the spindle. The spindle housing has an air supply passage for supplying air to the air bearing, an air supply port connected to the air supply passage, an air discharge passage, and an air discharge port. The air supply port is connected through an air supply line to an air source. The air supply line is provided with a pressure gauge and a flowmeter. A first allowable value is previously set for the pressure to be detected by the pressure gauge, and a second allowable value is previously set for the flow rate to be detected by the flowmeter.

A self-centering grinding wheel assembly that includes a spindle shaft including a conical-shaped end, a grinding wheel, and a grinding wheel adapter. The grinding wheel adapter affixed to the grinding wheel. A plurality of alignment members disposed radially within the grinding wheel adapter. Each of the plurality of alignment members include a tapered surface that conforms to a conical end of the spindle shaft. The plurality of alignment members slide radially with the grinding wheel adapter. The plurality of alignment members self-center the grinding wheel adapter on the spindle shaft in response to the grinding wheel adapter being assembled to the conical end of the conical shaft.

A self-centering grinding wheel assembly that includes a spindle shaft including a conical-shaped end, a grinding wheel, and a grinding wheel adapter. The grinding wheel adapter affixed to the grinding wheel. A plurality of alignment members disposed radially within the grinding wheel adapter. Each of the plurality of alignment members include a tapered surface that conforms to a conical end of the spindle shaft. The plurality of alignment members slide radially with the grinding wheel adapter. The plurality of alignment members self-center the grinding wheel adapter on the spindle shaft in response to the grinding wheel adapter being assembled to the conical end of the conical shaft.