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 . <EOS>