Abstract: A method for producing an ?-olefin oligomer composition includes: an oligomerization step A1 of oligomerizing an ?-olefin with a metallocene catalyst to obtain an oligomer (a); a distillation separation step A2 of distilling and separating the oligomer (a) to obtain a high molecular weight fraction (a1) and a low molecular weight fraction (a2); an oligomerization step B1 of oligomerizing an ?-olefin oligomer containing the low molecular weight fraction (a2) with an acid catalyst to obtain an oligomer (b); and a mixing step C of mixing a portion of the oligomer (a) or a hydrogenated product thereof and a portion or a whole of the oligomer (b), an isomer thereof, or a hydrogenated isomer thereof.

Abstract: The present invention provides a checking tool for a tube coupler with which it is possible to visually check an attachment state of the tube coupler. A checking tool 10 for a tube coupler according to the present invention is a checking tool configured to be attached to a tube coupler 30, the tube coupler being formed of a first coupling piece 31 and a second coupling piece 35 hingedly connected to each other so as to be able to be opened and closed, being configured to couple tubes to each other with use of the first coupling piece and the second coupling piece, and having hook pieces 33 and 37 that are provided protruding from outer circumferential surfaces of the first coupling piece and the second coupling piece.

Abstract: The present invention provides a clamping jig for tube connection with which it is possible to clamp tubes even in a small and narrow space. A clamping jig for tube connection 10 according to the present invention is a clamping jig for tube connection that clamps joint-equipped tubes 60, each tube including a protruding collar portion 63 at a position rearward of its leading end.

Abstract: The present invention provides a checking tool for a tube coupler with which it is possible to visually check an attachment state of the tube coupler. A checking tool 10 for a tube coupler according to the present invention is a checking tool configured to be attached to a tube coupler 30, the tube coupler being formed of a first coupling piece 31 and a second coupling piece 35 hingedly connected to each other so as to be able to be opened and closed, being configured to couple tubes to each other with use of the first coupling piece and the second coupling piece, and having hook pieces 33 and 37 that are provided protruding from outer circumferential surfaces of the first coupling piece and the second coupling piece.

Abstract: The present invention provides a clamping jig for tube connection with which it is possible to clamp tubes even in a small and narrow space. A clamping jig for tube connection 10 according to the present invention is a clamping jig for tube connection that clamps joint-equipped tubes 60, each tube including a protruding collar portion 63 at a position rearward of its leading end.