A grinding apparatus has a grinding wheel fastened to a mount disk connected a spindle by a plurality of bolts. The mount disk has at least three threaded holes and a plurality of protrusions protruding from a mount surface thereof. Each of the bolts includes an externally threaded shank, a neck coupled to the externally threaded shank, and an engaging flange coupled to the neck and extending radially outwardly. The grinding wheel includes an annular open hole defined in a mating surface of an annular base for mating with the mount surface, an annular slot that is wider than the annular open hole and is fluidly connected to the annular open hole, at least three insertion holes in the annular open hole for allowing the engaging flange to be inserted into the annular slot, and a plurality of protrusion insertion holes for receiving the engaging flanges of the bolts.

The disclosed technology includes an abrasive cutting tool having a plurality of segments arranged around a periphery of the cutting tool. The plurality of segments can include a first segment having a first portion having a first concentration of abrasive material, and a second portion having a second concentration of abrasive material. The second concentration can be less than the first concentration. The cutting tool can have a second segment having a third portion having a concentration of abrasive material that can be similar to the concentration of the first portion, and a fourth portion having a concentration of abrasive material that can be similar to the concentration of the second portion. The first portion and the second portion can be reciprocally arranged in relation to the third portion and the fourth portion around the periphery of the cutting tool.

A fixed abrasive article having a body including abrasive particles contained within a bond material, the abrasive particles including shaped abrasive particles or elongated abrasive particles having an aspect ratio of length:width of at least 1.1:1, each of the shaped abrasive particles or elongated abrasive particles having a predetermined position or a predetermined three-axis orientation.

The grinding device is for removing a collapsed liner inside a pipe. The grinding device has a connector for a drive shaft, a body rotatable around a rotation axis with the drive shaft and grinding cutters attached to the body. The grinding cutters have cutting edges provided in a plane perpendicular to the rotation axis of the body and the grinding device further has an outer periphery isolated from rotation of the body by bearings.

The grinding device is for removing a collapsed liner inside a pipe. The grinding device has a connector for a drive shaft, a body rotatable around a rotation axis with the drive shaft and grinding cutters attached to the body. The grinding cutters have cutting edges provided in a plane perpendicular to the rotation axis of the body and the grinding device further has an outer periphery isolated from rotation of the body by bearings.

A high-rotational speed cup-shaped grinding wheel includes an annular base, several blades and a flow splitting structure. The blades are fixed on a side of the base at an interval in a circumferential direction to form a blade ring. The side of the blade ring away from the base forms an annular working surface, and two adjacent blades are spaced apart from each other to form a water passage channel for delivering cooling water to the working surface. The flow splitting structure is fixed on the blade ring and splits the cooling water into two branches, where a first branch delivers the cooling water to an outer area of the working surface, and a second branch delivers the cooling water to an inner area of the working surface, and then delivers the cooling water from an inner area of the working surface to an outer side area thereof.

A machining segment for a machining tool which is rotatable in a direction of rotation about an axis of rotation includes an underside where the machining segment is connectable to a basic body of the machining tool by the underside. The machining segment has a machining zone of a matrix material and a plurality of first hard material particles that are disposed in the matrix material in accordance with a defined particle pattern. An upper side of the machining segment, opposite from the underside, is divided into a plurality of machining regions, which include respective ones of the plurality of first hard material particles, and a plurality of matrix regions which are built up from the matrix material. At least one of the plurality of machining regions has with respect to an adjacent matrix region a projection that is greater than 400 μm.

A machining segment for a machining tool which is rotatable in a direction of rotation about an axis of rotation includes an underside where the machining segment is connectable to a basic body of the machining tool by the underside. The machining segment has a machining zone of a matrix material and a plurality of first hard material particles that are disposed in the matrix material in accordance with a defined particle pattern. An upper side of the machining segment, opposite from the underside, is divided into a plurality of machining regions, which include respective ones of the plurality of first hard material particles, and a plurality of matrix regions which are built up from the matrix material. At least one of the plurality of machining regions has with respect to an adjacent matrix region a projection that is greater than 400 μm.

A tool-cooling mechanism includes a grinding tool. The grinding tool is provided with a converging disc, and the converging disc rotates with the grinding tool to draw external cooling water into the grinding tool for convergence, and then radially conveys the cooling water as converged toward an inner wall of the grinding tool, such that the cooling water can flow to a grinding surface along the inner wall of the grinding tool. The cooling water is allowed to enter via a water inlet and cool the grinding surface smoothly even when the grinding tool is rotating at a high speed, such that the cooling water can be prevented from passing through the grinding tool axially and failing to cool the grinding surface. In addition, the grinding surface is cooled after the cooling water as dispersed and atomized by the rotation of the grinding tool is converged.

Abrasive preforms include a frame having first and second opposed parallel major surfaces. The first major surface has a plurality of first cavities formed therein. The second major surface optionally has a plurality of second cavities formed therein. The frame comprises a binder precursor material. Abrasive particles are disposed in at least a portion of the plurality of first cavities and optional plurality of second cavities. Methods of making abrasive articles using the abrasive preforms and bonded abrasive articles preparable thereby are also disclosed.