A threaded connection for steel pipes is provided that exhibits improved sealability against the
external pressure while maintaining the sealability against the
internal pressure. A threaded connection for steel pipes includes a pin and a box. The pin includes a
nose, a tapered inner male thread, a tapered outer male thread, a pin inner sealing surface, a pin intermediate
shoulder surface, a pin intermediate sealing surface, and a pin annular portion. The box includes a recess corresponding to the
nose, a tapered inner female thread, a tapered outer female thread, a box inner sealing surface, a box intermediate
shoulder surface, a box intermediate sealing surface, and a box annular portion. The threaded connection satisfies expressions (1) and (2), provided below. α1 is a taper slope of the inner male thread, and α2 is a taper slope of the outer male thread.α1>α2,and(1)0.5≦L1α1L2α2≦1.2(2)In expression (2), L1 is a distance between the tip of the pin and the pin intermediate
shoulder surface as measured along the
pipe-axis direction when the pin and box have not been made up, and L2 is a distance between the box intermediate shoulder surface and the tip of the box as measured along the
pipe-axis direction when the pin and box have not been made up.