Abstract: Provided is a casing protection bit mounted on a casing tube in combination with a cutter bit to prevent abrasion or chipping of the cutter bit. The present invention is to provide a casing protection bit 1 to be mounted on a casing tube, the casing protection bit including: a base portion 2 that protrudes in an axial direction of the casing tube, the base portion having a mountain shape; and two leg portions 3 and 4 extending continuously with the base portion 2 and facing each other at a predetermined distance. In the casing protection bit cemented carbide tips 5a to 5j are disposed on all planes of the base portion 2 except for a plane from which the leg portions 3 and 4 extend.

Abstract: An auger bit mounted on an auger head and having improved excavation efficiency is provided. The present invention is an auger bit 11 mounted on an auger head, the auger bit including: a base part 12 having a leading end protruding in an axial direction of the auger head; and two leg parts 13 and 14 continuously extending from the base part and facing each other at a predetermined interval, the base part includes a plane part 12a parallel to and continuous with planes of the leg parts, first tilted parts 12b to 12d that are tilted from the plane part toward a side closer to the leading end in the axial direction of the auger head, side surface parts 12e and 12f continuous with the first tilted parts, and a second tilted part 12g tilted from the first tilted parts toward a side closer to the leg parts in the axial direction of the auger head, and the plane part and the leg part each have a shape curved at a predetermined curvature relative to the axial direction of the auger head.

Abstract: The invention is a multidirectional auger bit mounted on an auger head, and includes a base portion having a distal end that protrudes in an axial direction of the auger head, and leg portions that is continuous with the base portion. The base portion includes a flat portion that is continuous with the leg portion, first inclined portions that are inclined from the flat portion toward a distal end side in the axial direction of the auger head, left and right side surface portions that are continuous from the first inclined portion, and a second inclined portion that is inclined from the first inclined portion toward a leg portion side in the axial direction of the auger head.

Abstract: A casing-tube cutter bit applicable to both-directional rotation and having high excavation performance is provided. A casing-tube cutter bit includes a mounting part constituted by two members facing each other at a predetermined interval, and an excavation part formed continuously with the mounting part and having a leading end at which a plurality of ultrahard chips are disposed at a predetermined interval, the excavation part includes a central part, and first and second tilt parts tilted on both sides of the central part, the first tilt part is formed in a first length at a first tilt angle, the second tilt part is formed in a second length at a second tilt angle, the first tilt angle is equal to the second tilt angle, and the first length is shorter than the second length.

Abstract: An auger bit mounted on an auger head and having improved excavation efficiency is provided. The present invention is an auger bit 11 mounted on an auger head, the auger bit including: a base part 12 having a leading end protruding in an axial direction of the auger head; and two leg parts 13 and 14 continuously extending from the base part and facing each other at a predetermined interval, the base part includes a plane part 12a parallel to and continuous with planes of the leg parts, first tilted parts 12b to 12d that are tilted from the plane part toward a side closer to the leading end in the axial direction of the auger head, side surface parts 12e and 12f continuous with the first tilted parts, and a second tilted part 12g tilted from the first tilted parts toward a side closer to the leg parts in the axial direction of the auger head, and the plane part and the leg part each have a shape curved at a predetermined curvature relative to the axial direction of the auger head.

Abstract: Provided is a casing protection bit mounted on a casing tube in combination with a cutter bit to prevent abrasion or chipping of the cutter bit. The present invention is to provide a casing protection bit 1 to be mounted on a casing tube, the casing protection bit including: a base portion 2 that protrudes in an axial direction of the casing tube, the base portion having a mountain shape; and two leg portions 3 and 4 extending continuously with the base portion 2 and facing each other at a predetermined distance. In the casing protection bit cemented carbide tips 5a to 5j are disposed on all planes of the base portion 2 except for a plane from which the leg portions 3 and 4 extend.

Abstract: A casing-tube cutter bit applicable to both-directional rotation and having high excavation performance is provided. A casing-tube cutter bit includes a mounting part constituted by two members facing each other at a predetermined interval, and an excavation part formed continuously with the mounting part and having a leading end at which a plurality of ultrahard chips are disposed at a predetermined interval, the excavation part includes a central part, and first and second tilt parts tilted on both sides of the central part, the first tilt part is formed in a first length at a first tilt angle, the second tilt part is formed in a second length at a second tilt angle, the first tilt angle is equal to the second tilt angle, and the first length is shorter than the second length.