A processing apparatus includes a cutting blade mounted on a spindle, the cutting blade having a cutting edge for cutting a workpiece held on a holding table, a measuring portion for measuring an edge projection amount of the cutting edge at a predetermined frequency, and a data processing portion. The data processing portion includes a lower limit recording portion for recording a lower limit of the edge projection amount of the cutting edge as an allowable limit for use of the cutting blade, a storing portion for storing blade information including the edge projection amount measured by the measuring portion and a cutting distance traveled by the cutting blade at the time of measurement of the edge projection amount.

In an outer blade cutting wheel comprising an annular thin disc base of cemented carbide having an outer diameter of 80-200 mm, an inner diameter of 30-80 mm, and a thickness of 0.1-1.0 mm, and a blade section disposed on an outer periphery of the base, the blade section comprises diamond grains and/or CBN grains bound with a metal bond having a Young's modulus of 0.7-4.0×10.sup.11 Pa and has a thickness which is greater than the thickness of the base by at least 0.01 mm. The outer blade cutting wheel is capable of cutting a workpiece at a high accuracy and a reduced allowance, improves machining yields, and reduces machining costs.

In an outer blade cutting wheel comprising an annular thin disc base of cemented carbide having an outer diameter of 80-200 mm, an inner diameter of 30-80 mm, and a thickness of 0.1-1.0 mm, and a blade section disposed on an outer periphery of the base, the blade section comprises diamond grains and/or CBN grains bound with a metal bond having a Young's modulus of 0.7-4.0×10.sup.11 Pa and has a thickness which is greater than the thickness of the base by at least 0.01 mm. The outer blade cutting wheel is capable of cutting a workpiece at a high accuracy and a reduced allowance, improves machining yields, and reduces machining costs.

Tool cores may have removable sections, which may be removable without damaging, cutting or severing attachment configurations for the removable sections. The removable sections may be handled simultaneously. Moving parts used to facilitate removal of the removable sections may be secured in a pre-loaded configuration.

Method for producing a machining segment (51) for a machining tool from a powdered or granular first matrix material (56), first hard material particles (57), which are arranged according to a defined first particle pattern, and second hard material particles (58), which are arranged according to a defined second particle pattern, the machining segment being connected by an underside (61) to a basic body of the machining tool. The machining segment (51) has on the side surfaces a projection of the second hard material particles (58) with respect to the first matrix material (56).

Method for producing a green body for a machining segment (51) from a powdered or granular first matrix material (56), first hard material particles (57) and second hard material particles (58), the machining segment being connected by an underside (61) to a basic body of a machining tool. The machining segment (51) has a projection of the second hard material particles (58) with respect to the first matrix material (56) on the side surfaces.

Method for producing a green body for a machining segment (51) from a powdered or granular first matrix material (56), first hard material particles (57) and second hard material particles (58), the machining segment being connected by an underside (61) to a basic body of a machining tool. The machining segment (51) has a projection of the second hard material particles (58) with respect to the first matrix material (56) on the side surfaces.

Method for producing a green body for a machining segment (51) from a powdered or granular first matrix material (56) and first hard material particles (57), the machining segment being connected by an underside (61) to a basic body of a machining tool. The machining segment (51) has a projection (Δ) of the first hard material particles (57) on an upper side (62) opposite from the underside (61).

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, including a placement angle ranging from +90 degrees to −90 degrees and a rake angle ranging from +90 degrees to −90 degrees.

An annular grindstone includes a grindstone portion including a binding material, and abrasive grains which are dispersed into the binding material to be fixed, in which the binding material contains a nickel-iron alloy. Preferably, a contained ratio of iron in the nickel-iron alloy is in a range of 5 wt % or more to less than 60 wt %. More preferably, a contained ratio of iron in the nickel-iron alloy is in a range of 20 wt % or more to 50 wt % or less. Preferably, the annular grindstone includes the grindstone portion only. In addition, the annular grindstone further includes an annular base including a grip portion, in which the grindstone portion is exposed at an outer peripheral edge of the annular base.