A threaded connection for steel pipe, comprising: a tubular pin formed by one tip portion of a steel pipe; and a tubular box adapted to be made up on the pin as the pin is inserted into the box, the pin including: a pin shoulder provided on the tip portion of the pin, the pin shoulder having a toroidal surface; a male thread provided on an outer peripheral surface of the pin, the male thread being a wedge thread; and a pin seal provided between the pin shoulder and the male thread, the pin seal being provided on the outer peripheral surface of the pin, the box including: a box shoulder corresponding to the pin shoulder and provided on an innermost face of the box, the box shoulder having a toroidal surface; a female thread corresponding to the male thread and provided on an inner peripheral surface of the box, the female thread being a wedge thread; and a box seal corresponding to the pin seal and provided on the inner peripheral surface of the box, wherein the pin shoulder is spaced apart from the box shoulder when the pin and the box have been made up, and the threaded connection satisfies the following expression,: characterized in that: 3 % ≤ LP − SP / LP ≤ 7 % where, in expression, LP is the pitch between loading flanks of the male thread, and SP is the pitch between stabbing flanks of the male thread. a tubular pin formed by one tip portion of a steel pipe; and a tubular box adapted to be made up on the pin as the pin is inserted into the box, the pin including: a pin shoulder provided on the tip portion of the pin, the pin shoulder having a toroidal surface; a male thread provided on an outer peripheral surface of the pin, the male thread being a wedge thread; and a pin seal provided between the pin shoulder and the male thread, the pin seal being provided on the outer peripheral surface of the pin, a pin shoulder provided on the tip portion of the pin, the pin shoulder having a toroidal surface; a male thread provided on an outer peripheral surface of the pin, the male thread being a wedge thread; and a pin seal provided between the pin shoulder and the male thread, the pin seal being provided on the outer peripheral surface of the pin, the box including: a box shoulder corresponding to the pin shoulder and provided on an innermost face of the box, the box shoulder having a toroidal surface; a female thread corresponding to the male thread and provided on an inner peripheral surface of the box, the female thread being a wedge thread; and a box seal corresponding to the pin seal and provided on the inner peripheral surface of the box, wherein the pin shoulder is spaced apart from the box shoulder when the pin and the box have been made up, and a box shoulder corresponding to the pin shoulder and provided on an innermost face of the box, the box shoulder having a toroidal surface; a female thread corresponding to the male thread and provided on an inner peripheral surface of the box, the female thread being a wedge thread; and a box seal corresponding to the pin seal and provided on the inner peripheral surface of the box, wherein the pin shoulder is spaced apart from the box shoulder when the pin and the box have been made up, and the threaded connection satisfies the following expression,: characterized in that: 3 % ≤ LP − SP / LP ≤ 7 % where, in expression, LP is the pitch between loading flanks of the male thread, and SP is the pitch between stabbing flanks of the male thread. characterized in that: 3 % ≤ LP − SP / LP ≤ 7 % where, in expression, LP is the pitch between loading flanks of the male thread, and SP is the pitch between stabbing flanks of the male thread.