Provided is a method for preventing metal contamination during cutting of a polycrystalline silicon rod. A method for cutting a polycrystalline silicon rod (S) includes the step of cutting the polycrystalline silicon rod (S) by using a cutting tool (133). The step of cutting includes: delivering a liquid (L1) to a cutting position of the polycrystalline silicon rod (S) through a first nozzle (14); and delivering a liquid (L2) to a surface of the polycrystalline silicon rod (S) through a second nozzle (15).

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 method for processing a ceramic honeycomb structure, the method comprising subjecting an outer peripheral surface of the ceramic honeycomb structure to centerless grinding in an in-feed mode by bringing a rotationally driving grinding wheel into contact with the outer peripheral surface of the ceramic honeycomb structure rotationally supported by an adjusting wheel, a blade, and a press roller.

A method for processing a ceramic honeycomb structure, the method comprising subjecting an outer peripheral surface of the ceramic honeycomb structure to centerless grinding in an in-feed mode by bringing a rotationally driving grinding wheel into contact with the outer peripheral surface of the ceramic honeycomb structure rotationally supported by an adjusting wheel, a blade, and a press roller.

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.