| abstract |
Provided is a threaded joint for pipes, which has a large delta torque and can be screw-tightened with both of a tightening torque equal to the conventional one and a tightening torque higher than the conventional one. The threaded joint for pipes according to the present disclosure is equipped with a pin (3), a box (4), a shoulder part plating layer (5) and a non-shoulder part plating layer (6). The outermost surface layer of the shoulder part plating layer (5) is a high-friction-coefficient plating layer (50), and the shoulder part plating layer (5) is arranged on a pin-side shoulder part (33) and/or a box-side shoulder part (43). The outermost surface layer of the non-shoulder part plating layer (6) is a low-friction-coefficient plating layer (60) that has a lower friction coefficient than that of the high-friction-coefficient plating layer (50), and the non-shoulder part plating layer (6) is arranged on at least a part of a pin-side screw part (31), a pin-side metal seal part (32), a box-side screw part (41) or a box-side metal seal part (42). |