An epoxy-functional coupling agent comprises a reaction product of a polyepoxide and an aminosilane represented N by the formula HNR.sup.1R.sup.2. R.sup.1 represents ZSiL.sub.3 and R.sup.2 represents ZSiL.sub.3 or an alkyl group having from 1 to 4 carbon atoms. Each Z independently represents a divalent linking group having from 1 to 18 carbon atoms, and each L independently represents a hydrolyzable group. The coupling agent may be used to treat a substrate such as an abrasive particle, which may be included in a resin bond abrasive article.

An epoxy-functional coupling agent comprises a reaction product of a polyepoxide and an aminosilane represented N by the formula HNR.sup.1R.sup.2. R.sup.1 represents ZSiL.sub.3 and R.sup.2 represents ZSiL.sub.3 or an alkyl group having from 1 to 4 carbon atoms. Each Z independently represents a divalent linking group having from 1 to 18 carbon atoms, and each L independently represents a hydrolyzable group. The coupling agent may be used to treat a substrate such as an abrasive particle, which may be included in a resin bond abrasive article.

A segment for an abrasive article is disclosed. The segment can include a segment body that can have a first face that can extend along a length of the segment body on a first side of the segment body and a second face that can extend along the length of the segment body on a second side of the segment body opposite the first side. A gullet wall can extend from the first face to the second face. The gullet wall can extend along a gullet. The segment can also include a recessed region that can extend into one or both of the first and second faces. The recessed region can include a gullet portion extending at least partially along the gullet wall.

A segment for an abrasive article is disclosed. The segment can include a segment body that can have a first face that can extend along a length of the segment body on a first side of the segment body and a second face that can extend along the length of the segment body on a second side of the segment body opposite the first side. A gullet wall can extend from the first face to the second face. The gullet wall can extend along a gullet. The segment can also include a recessed region that can extend into one or both of the first and second faces. The recessed region can include a gullet portion extending at least partially along the gullet wall.

A rare earth magnet block is cutoff machined into pieces by rotating a plurality of cutoff abrasive blades. Improvements are made by starting the machining operation from the upper surface of the magnet block downward, interrupting the machining operation, turning the magnet block upside down, placing the magnet block such that the cutoff grooves formed before and after the upside-down turning may be aligned with each other, and restarting the machining operation from the upper surface of the upside-down magnet block downward until the cutoff grooves formed before and after the upside-down turning merge with each other.

Disc-shaped sanding element (1) and method for manufacturing this sanding element (1) with a circular circumference with at least two layers (4,5,6) bonded to each other containing abrasive grains (11, 12), wherein these layers (4,5,6) extend at least to the circumference of the sanding element (1) in order to form a sanding edge (8) on this circumference (7), wherein each of these layers (4,5,6) has layer properties including compressibility, abrasive grain density, abrasive grain size and grain material. The layers (4,5,6) contain a three-dimensional thread or fibre structure in which said abrasive grains (11,12) are distributed, wherein adjacent layers (4,5,6) have at least one different layer property.

A cutting device for cutting a pipe having a pipe wall. The cutting device includes an elongate carrier having a tool end which is engageable with a power tool and an opposed free end. The device includes a guide wheel located at the free end of the carrier which is loosely mounted thereon for rotation relative thereto, having a bearing surface extending parallel to a longitudinal axis of the carrier. The device also includes a cutting element having a peripheral cutting edge which is located adjacent to the guide wheel being positioned intermediate the guide wheel and the tool end. The cutting element is of greater transverse dimension than the guide wheel so that when the bearing surface bears against an internal surface of the pipe the distance between the cutting edge of the cutting element and the bearing surface enables the cutting element to cut through the pipe wall.

A cutting device for cutting a pipe having a pipe wall. The cutting device includes an elongate carrier having a tool end which is engageable with a power tool and an opposed free end. The device includes a guide wheel located at the free end of the carrier which is loosely mounted thereon for rotation relative thereto, having a bearing surface extending parallel to a longitudinal axis of the carrier. The device also includes a cutting element having a peripheral cutting edge which is located adjacent to the guide wheel being positioned intermediate the guide wheel and the tool end. The cutting element is of greater transverse dimension than the guide wheel so that when the bearing surface bears against an internal surface of the pipe the distance between the cutting edge of the cutting element and the bearing surface enables the cutting element to cut through the pipe wall.

A rare earth magnet block is cutoff machined into pieces by rotating cutoff abrasive blades. Improvements are made by setting the blades on one side of the magnet block, rotating the blades, starting machining operation to form cutting grooves in the magnet block from one side, interrupting the machining operation, moving the blades to the other side of the magnet block, and restarting the machining operation to form cutting grooves in the magnet block from the other side, until the cutting grooves formed from the one and other sides merge with each other.

A cutting wheel includes a body having a bond material. The bond material comprises at least about 31 vol % of a total volume of the body. Additionally, the body includes abrasive particles contained within the bond material. The abrasive particles include a first type of abrasive particle including black alumina with at least about 10 vol % of a total volume of the abrasive particles including black alumina. In some instances the cutting wheel can include a chop saw, while in other situations, the cutting wheel can include a cut-off wheel.