To provide a steel pipe with flare having the flare having excellent rigidity, strength, and durability and large width being suitable for a steel pipe column of a steel pipe, a fluid transportation pipe, and a rotary press-fitting steel pipe pile.

In this steel pipe with flare 1 being integral with a steel pipe base material 3 and provided with the collar-like flare 2 having plastic machining texture at one end or both ends, outside diameter of the steel pipe base material 3 is 60 to 400 mm, and width of the flare is 40 mm or more. Preferably, the maximum value of wall thickness of the flare 2 is 1.15 times or more wall thickness of the steel pipe base material 3.