The invention has a turnback roll which can transfer and guide a polishing tap in a tangential direction of a pressure contacting roll, a vertical oscillation mechanism which linearly oscillates the pressure contacting roll in a tangential direction of a ball groove while being orthogonal to a rotating axis line, and a horizontal oscillation mechanism which linearly oscillates the pressure contacting roll in a direction of a rotating axis line toward both inner side surfaces of the ball groove. The ball groove can be securely polished by the polishing tape on the basis of the continuous or intermittent transfer of the polishing tape and the linear oscillating motion of the ball groove. It is possible to improve a polishing precision, it is possible to improve a surface roughness of the ball groove and it is possible to improve a polishing workability of the ball groove.

A method of forming a curved slot in a turbine disk includes the steps of forming a pre-slot in the turbine disk and finishing the pre-slot to form a slot that receives a portion of a turbine blade. The turbine disk including a first face, an opposing second face, and an outer perimeter surface extending between the first face and the opposing second face. The pre-slot includes a first curved wall and a second curved wall that each extend between the first face and the opposing second face. An intersection between the outer perimeter surface and each of the first curved wall and the second curved wall is defined by a curved line.

Thread repair tools having (i) a disc-shaped member with an axis of rotation extending through and dissecting first and second major surfaces of the disc-shaped member, (ii) a shaft fixedly connected to or fixedly connectable to the disc-shaped member, with the shaft extending from the second major surface of the disc-shaped member along the axis of rotation; and (iii) an abrasive surface along an outer periphery of the disc-shaped member are disclosed. Methods of making the thread repair tools, and methods of using the thread repair tools are also disclosed. Methods of using the thread repair tools include a method of: (i) connecting the thread repair tool to a hand-held powered device capable of rotating the thread repair tool along the axis of rotation of the thread repair tool, and (ii) abrading an object with the disc-shaped member of the thread repair tool as the thread repair tool is rotated along the axis of rotation by the hand-held powered device.

There is provided a method for processing a raceway groove configured to circumferentially form a to-be-processed side raceway groove on a surface to be processed of a workpiece, the to-be-processed side raceway groove is configured to be brought into rolling contact with a rolling element, and the surface to be processed is a cylindrical circumferential surface. The method for processing a raceway groove includes: arranging a processing rolling element rotatably between the to-be-processed side raceway groove and a tool side circumferential surface which is opposed to the surface to be processed and which is a cylindrical circumferential surface of a machining tool; rotating the machining tool relatively with respect to the workpiece; and performing a burnishing process on the to-be-processed side raceway groove.

Described is a method for grinding workpieces, which comprise at least one cylindrical and profiled portion each, on one and the same grinding machine. The workpiece is ground initially in a first grinding operation in a first clamping in the grinding machine, said first grinding operation being followed by a second grinding operation once the first clamping has been released and then, before the start of the second grinding operation, a second clamping has been generated.

A gear grinding machine uses a grindstone tool, having an outer circumference that includes a thread, to grind a tooth surface of a gear workpiece. In this case, coolant is supplied toward the tooth surface from a trailing side in a rotation direction of the gear workpiece through a space between the grindstone tool and the gear workpiece. The coolant is drawn into the meshing portion between the grindstone tool and the gear workpiece by the rotation of the gear workpiece and the movement of the thread of the grinding tool.

A method for manufacturing a rotor includes the following operations: the clamping of a workpiece in a grinding machine; the performance of one or more cylindrical grinding operations whereby a rotor shaft section is ground to the desired diameter with a cylindrical grinding disk; the performance of one more profile grinding operations whereby a rotor body is profiled with a profile grinding disk. During the manufacture of the rotor in the grinding machine, the workpiece is not undamped and the cylindrical grinding operations and the profile grinding operations are done with the same grinding machine.

In a plastic nut for a ball screw formed by injection molding fiber reinforced plastic, the reduction in precision over time due to wear is minimized. A thread groove is ground until the fibers in matrix plastic are exposed on the surface of the thread groove.

The invention has a turnback roll which can transfer and guide a polishing tap in a tangential direction of a pressure contacting roll, a vertical oscillation mechanism which linearly oscillates the pressure contacting roll in a tangential direction of a ball groove while being orthogonal to a rotating axis line, and a horizontal oscillation mechanism which linearly oscillates the pressure contacting roll in a direction of a rotating axis line toward both inner side surfaces of the ball groove. The ball groove can be securely polished by the polishing tape on the basis of the continuous or intermittent transfer of the polishing tape and the linear oscillating motion of the ball groove. It is possible to improve a polishing precision, it is possible to improve a surface roughness of the ball groove and it is possible to improve a polishing workability of the ball groove.

A method of manufacturing an endodontic instrument includes providing a metal alloy powder and forming an endodontic instrument by depositing and heating successive layers of the metal alloy poser according to an additive manufacturing process. Forming an endodontic instrument according to an additive manufacturing process allows for advanced features such as one or more voids in the interior region of the instrument.