Method for manually cutting irregular plate tube penetration hole of arc circular tube

The invention belongs to the cutting technology field of a circular tube penetration hole of a steel building structure and particularly relates to a method for manually cutting an irregular plate tube penetration hole of an arc circular tube. The cutting method comprises the following steps of a, providing an arc circular penetration tube deepening drawing; b, lofting according to a deepened part drawing, locating the position of a circular tube to allow a penetration plane to be in a horizontal plane, marking out a three-point locating point according to requirements of the drawing, and popping up a penetration position line in a line popping way; repeatedly drawing the line for each penetration hole according to the way; c, according to the drawn position line, rechecking the penetration line, upon the correct size, and cutting the irregular penetration hole along the drawn position line.