This is the case: (7800-600) * (800*2+400) forgot, 800 also minus plate thickness
Is the template area, there are two times in each cross beam, then the results of the calculation of the sub beam cross-sectional area (a few minus a few) is the
The two cross KL76, distance of each cross axis of the pillar width is Jingchang (beam by beam, high *2+ Liang Kuan)
