Car frame girder

The invention discloses a car frame girder, which comprises a flank, an upper wing surface and a lower wing surface which are perpendicular to the flank. The upper wing surface and the lower wing surface are located at the upper end and the lower end of the flank; the flank is provided with mounting holes and via holes; the mounting holes are arranged in four rows in parallel up and down, the via holes are in one row, the row of the via holes are located at the middle of the middle two rows of the mounting holes; the distances of adjacent rows of the mounting holes are the same, the pitches of each adjacent row of the mounting holes are the same; the centers of the via holes are located at the middles of the two adjacent rows of the mounting holes. The standardized layout of the hole locations has a rule to follow during designing, manufacturing, assembling and inspecting processes, the standardization, serialization, generalization and lightweight of the car frame and the vehicle are facilitated, the efficie