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AssigneesMitsubishi Materials Corporation, Furukawa Rock Drill Co., Ltd.
InventorsMasaya Hisada, Masahiro Koizumi, Takashi Suzuki
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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.
A drill rod comprising a fitting portion which protrudes toward a distal end of the drill rod and extends along a first axial line, wherein
A drill bit comprising a fitting hole which is opened toward a proximal end of the drill bit and extends along a second axial line, wherein
Dependencies are inferred from the claim text.