Electric resistance welded steel pipes and line pipes

An electric resistance welded steel pipe comprising a base metal zone and an electric resistance weld, wherein

• when the electric resistance welded steel pipe is tested by a Vickers test with a load of 10 gf with respect to a location 1 mm deep from an inner surface of the electric resistance weld, a location 1 mm deep from an outer surface of the electric resistance weld, a location 1 mm deep from an inner surface of the base metal zone, and a location 1 mm deep from an outer surface of the base metal zone,
• indentations in each of the locations have:
• a ratio of the number of indentations with a hardness greater than or equal to an average hardness plus 40 HV of 0.30 or less, and
• a ratio of the number of indentations having an eccentricity E of 0.20 or more of 0.40 or less, wherein
• the eccentricity E is a value calculated from expression (1) below where Lmax, Lmin, and Lave are the maximum value, the minimum value, and the average, respectively, of the lengths of line segments OA, OB, OC, and OD where O is the intersection point of the diagonals of the indentation, and A, B, C, and D are the vertices of the indentation in counterclockwise order,
• E
• =
• (
• L
• max
• -
• L
• min
• )
• /
• L
• ave
• .
• (
• 1
• )