Abstract: A hose coupling 1 includes a nipple 3 in which a tubular part for inserting a hose 2 externally, an annular groove part for inserting a tip of the hose 2, and an attachment part for a separate part are formed in that order along the hose insertion direction A; a nut 4 having a screw part that is screwed onto the outer circumferential surface of the nipple 3 in a state that the tip of the hose 2 is inserted into the annular groove part, and a thickened part that is continuously formed from the screw part and located on the outer circumferential surface of the tubular part; and a sleeve 5 interposed between the tubular part and the thickened part, wherein the sleeve 5 has a thickness reduced part 10 on the inner circumferential surface thereof.

Abstract: A caulking die according to an embodiment of the present invention includes an end surface being connected to each of an upper surface and a lower surface. The end surface includes a first protruded part including a first top portion, a recessed groove, and a second protruded part including a second top portion in sequential order from the lower surface side toward the upper surface side. A length of the second top portion is larger than a length of the first top portion, and a height of the second protruded part is larger than a height of the first protruded part in a cross-sectional view perpendicular to a width direction of the end surface. A caulking tool includes the caulking die. A method for manufacturing a caulking joint uses the caulking tool.

Abstract: A caulking die according to an embodiment of the present invention includes an end surface being connected to each of an upper surface and a lower surface. The end surface includes a first protruded part including a first top portion, a recessed groove, and a second protruded part including a second top portion in sequential order from the lower surface side toward the upper surface side. A length of the second top portion is larger than a length of the first top portion, and a height of the second protruded part is larger than a height of the first protruded part in a cross-sectional view perpendicular to a width direction of the end surface. A caulking tool includes the caulking die. A method for manufacturing a caulking joint uses the caulking tool.

Abstract: Two false-twist belts are each entrained about crowned pulleys. The belts are arranged so that their outer-facing surfaces cross one another with one belt pressed against the other. Yarn is passed between these false-twist belts and twisted. The bending rigidity in the lateral direction of the false-twist belts is set to a value in which the outer-facing surfaces of the false-twist belts are rounded into a convex curvature at the position where the belts are pressed against each other.