Abstract: In an excavation tool of the present invention, an embedding hole is drilled in a distal end portion of a tool body which is rotated about an axis line O and is moved forward to a distal end side in a direction of the axis line O. In the embedding hole, an excavation tip in which an embedding portion having an outer cylindrical shape is formed integrally with a cutting edge portion inserts the embedding portion into the embedding hole and causes the cutting edge portion to protrude from the embedding hole. In this manner, the excavation tip is rotatable around a central axis C of the embedding portion during excavation, and is attached thereto by being locked so as not to slip toward a distal end side of the embedding portion 6 in a direction of the central axis C.

Abstract: An excavating tool includes a casing pipe that forms a cylindrical shape about an axis line and in which a stepped portion whose inner diameter is decreased by one step is formed in an inner peripheral portion of an distal end; an inner bit where a contact portion which can come into contact with the stepped portion is formed in an outer periphery, which is inserted into the casing pipe, and whose distal end portion protrudes from a distal end of the casing pipe; an engagement convex portion that is disposed on the outer periphery of the distal end portion of the inner bit so as to be retractable; a ring bit that forms an annular shape and is arranged around the distal end portion of the inner bit; and an engagement concave portion that is formed in an inner peripheral portion of the ring bit.

Abstract: An excavating tool includes a casing pipe that forms a cylindrical shape about an axis line and in which a stepped portion whose inner diameter is decreased by one step is formed in an inner peripheral portion of an distal end; an inner bit where a contact portion which can come into contact with the stepped portion is formed in an outer periphery, which is inserted into the casing, and whose distal end portion protrudes from a distal end of the casing pipe; an engagement convex portion that is disposed on the outer periphery of the distal end portion of the inner bit so as to be retractable; a ring bit that forms an annular shape and is arranged around the distal end portion of the inner bit; and an engagement concave portion that is formed in an inner peripheral portion of the ring bit.

Abstract: In an excavation tool of the present invention, an embedding hole is drilled in a distal end portion of a tool body which is rotated about an axis line O and is moved forward to a distal end side in a direction of the axis line O. In the embedding hole, an excavation tip in which an embedding portion having an outer cylindrical shape is formed integrally with a cutting edge portion inserts the embedding portion into the embedding hole and causes the cutting edge portion to protrude from the embedding hole. In this manner, the excavation tip is rotatable around a central axis C of the embedding portion during excavation, and is attached thereto by being locked so as not to slip toward a distal end side of the embedding portion 6 in a direction of the central axis C.

Abstract: Provided is an excavation tool for efficiently taking waste rocks produced during excavation into the inner peripheral side of a casing pipe. An excavation tool (10) includes a casing shoe (11), a casing pipe (15), a rod (60), a device (40), and an excavation bit (20). The excavation bit (20) has a head portion (22) and a skirt portion (23). The head portion (22) is provided with: a face flute (27), which is open into the tip face of the head portion and extends radially outward; a connection flute (28), which is integrally connected to the outer peripheral end of the face flute (27) and extends toward the rear end side, and an intake hole (29), which is integrally connected with the discharge flute (46) of the device (40) and is open to the inner peripheral side of the skirt portion (23) from the connection flute (28).

Abstract: The present invention relates to a hollow drilling steel rod including a stem portion and a thread portion positioned at an end portion in an axial direction with respect to the stem portion, the hollow drilling steel rod being constituted of a steel having a specific composition described in the present specification, in which the thread portion includes a thread having been subjected to a high frequency quenching, and the thread portion and the stem portion separate from each other have been joined by a friction welding.

Abstract: The present invention relates to a hollow drilling steel rod including a stem portion and a thread portion positioned at an end portion in an axial direction with respect to the stem portion, the hollow drilling steel rod being constituted of a steel having a specific composition described in the present specification, in which the thread portion includes a thread having been subjected to a high frequency quenching, and the thread portion and the stem portion separate from each other have been joined by a friction welding.

Abstract: A drill rod has a fitting portion protruding toward the distal end of the drill rod. The drill rod fitting portion further encompasses a parallel male thread portion in which a minimum distance from a first axial line in a cross-section perpendicular to the first axial line is constant; and a male thread ending portion is continuous with a proximal end of the parallel male thread portion. The minimum distance of the ending portion increases as a proximal end is approached. Furthermore, the fitting portion is formed such that the minimum distance does not decrease as the proximal end is approached from a distal end thereof. Additionally, the proximal end of the male thread ending portion is positioned where a distance from the first axial line gradually increases as the proximal end of the male thread ending portion is approached from the parallel male thread.

Abstract: Provided is an excavation tool for efficiently taking waste rocks produced during excavation into the inner peripheral side of a casing pipe and discharging the waste rocks to the outside. An excavation tool (10) includes a casing shoe (11), a casing pipe (15), a rod (60), a device (40), and an excavation bit (20). A discharge flute (46) for discharging the waste rocks is formed in the outer peripheral surface of the device (40). The excavation bit (20) has a head portion (22) and a skirt portion (23). The device (40) can be inserted into the inner periphery of the skirt portion (23).

Abstract: A drill rod having a fitting portion protruding toward the distal end and of the drill rod and extending along a first axial line, wherein the fitting portion includes: a parallel male thread portion in which a minimum distance from the first axial line in a cross-section perpendicular to the first axial line is constant; and a male thread ending portion which is continuous with a proximal end of the parallel male thread portion, and in which the minimum distance increases as approaching toward a proximal end thereof; wherein the fitting portion is formed such that the minimum distance does not decrease as approaching from a distal end to a proximal end thereof; and the proximal end of the male thread ending portion is positioned on a face where a distance from the first axial line gradually increases as approaching from the parallel male thread to the proximal end of the male thread ending portion.