Sampling ruler for drawing lines in spiral welded pipe

The utility model discloses a sampling ruler for drawing lines in a spiral welded pipe, which is applied to drawing lines on a steel tube. A rubber magnetic plate frame is a rectangular frame formed by adhering and fixing two long side strips and two short side strips and is provided with two impact sampling strips for drawing lines, which are parallel with the short side strips; and three impact sampling inner strips for drawing lines, which are perpendicular to the impact sampling strips for drawing lines, are fixed between the impact sampling strips for drawing lines. Two holes are respectively arranged in the middle of the two long side strips of the rubber magnetic plate frame; and the center connecting line of the two holes is parallel with the short side strips. The utility model has the beneficial effects that the sampling ruler can be adsorbed and fixed on the surface of the steel tube; an operator for drawing lines can flexibly finish sampling and drawing lines on the steel tube under the condition