Abstract: Provided are a drill that enhances work efficiency and process accuracy of a boring process, and a boring device enabling dust collection and recovery by using the drill. In a drill formed with a chip exhaust 102 along a center of an axis in a drill body 101, a large-diameter cylindrical body 101a with an outer diameter increased via a different level part G or G? is provided on a base end side of the drill body 101, first cutting edges 110 are provided on a tip part of the drill body, first scrap lead pockets 112 leading to the chip exhaust are provided in the vicinity of the first cutting edges 110, second cutting edges 120 are provided on the different level part, and second scrap lead pockets 122 leading to the chip exhaust are provided in the vicinity of the second cutting edges 120.

Abstract: A cutting tool is designed to prevent chip packing. The cutting tool includes a body that rotates about an axis center, a hole portion that is open in a tip end surface of the body, a wall portion that is formed of the hole portion and an outer circumferential surface of the body, a notch portion that is communicated with the hole portion, and a blade portion that is formed or held at a portion where the notch portion intersects with the tip end surface of the wall portion. The blade portion includes an inner side surface that passes through an inner end portion of a bottom blade and intersects with a rake surface through a ridge line. The inner side surface is inclined so that a distance between the inner side surface and the axis center is increased towards a direction opposite to the rotational direction of the body.

Abstract: A drill in which a flute is formed from a point to a base end side of a body of the drill, on a side face to be rotated about an axis, a cutting edge is formed between a wall surface of the flute which faces a drill rotational direction side and a flank at the point of the body, and a thinned portion is provided to a web portion of the point. The cutting edge is formed in a convex arc shape with a curvature radius 0.25 to 1 times a drill diameter; a radial rake angle at an outer peripheral portion of the cutting edge is ?60 to ?15 degrees; a corner portion, closer to the center of the point, of the thinned portion is formed in an arc shape with a curvature radius of at least 0.1 mm and not greater than 0.05 times the drill diameter; and the drill includes three flutes and three cutting edges.

Abstract: A neck portion grinding apparatus and method is designed to reduce working man-hours and to improve processing accuracy with respect to a processing of a workpiece. The neck portion grinding apparatus includes a grinding device having a disc-like grinding wheel and a wheel rotating device for rotating the grinding wheel, and a machine tool having a main shaft for rotatably supporting a rotating tool and a table mounting the grinding device thereon, and relatively moving the main shaft and the table by numeral control. A shape of a neck portion of the rotating tool can be changed by relatively moving the main shaft and the table while mutually rotating the rotating tool and the grinding wheel, and grinding the rotating tool by the grinding wheel.

Abstract: A radius endmill has a peripheral cutting edge, a bottom cutting edge, and a rounded corner cutting edges whose ridge line is defined by a circular arc having a given radius as measured in a side view of the endmill that is parallel to the axis. The rounded corner cutting edge is located in a corner portion of the endmill in which the outer peripheral and the axial end intersect each other such that the peripheral cutting edge and the bottom cutting edge are connected to each other through the rounded corner cutting edge. The bottom cutting edge has a radially inner end lying at the axis, and a radially outer end at which the bottom cutting edge is connected to the rounded corner cutting edge. The bottom cutting edge is curved such that its ridge line is defined by a circular arc as seen in a plan view of the endmill that is perpendicular to the axis.

Abstract: A drill in which a flute is formed from a point to a base end side of a body of the drill, on a side face to be rotated about an axis, a cutting edge is formed between a wall surface of the flute which faces a drill rotational direction side and a flank at the point of the body, and a thinned portion is provided to a web portion of the point. The cutting edge is formed in a convex arc shape with a curvature radius 0.25 to 1 times a drill diameter; a radial rake angle at an outer peripheral portion of the cutting edge is ?60 to ?15 degrees; a corner portion, closer to the center of the point, of the thinned portion is formed in an arc shape with a curvature radius of at least 0.1 mm and not greater than 0.05 times the drill diameter; and the drill includes three flutes and three cutting edges.