| 摘要 |
PROBLEM TO BE SOLVED: To easily and surely prevent occurrence of loosening or rattling between connected steel pipes.SOLUTION: One steel pipe 10 includes a male connection end portion 13 having a thread in the outer circumference thereof, and the other steel pipe 20 includes a female connection end portion 23 having a thread in the inner circumference thereof and threaded with the male connection end portion 13. In a structure where the one steel pipe 10 and the other steel pipe 20 are connected by threading the connection end portions 13, 23 with each other, a bolt having an uneven shape in the distal end portion thereof is threaded into a through hole 29, which the female connection end portion 23 comprises, from an outer circumferential surface 27 of the female connection end portion 23 to an inner circumferential surface 28 to press the distal end portion against an outer circumferential surface of the male connection end portion 13, thereby constituting a loosening prevention structure of steel pipe connection. |
