A large thin-wall casting part for aeroplane cracked many times when it was riveted with the skin and
resulted in serious security risk. The cause of the riveting crack was analyzed synthetically by macro and micro observation
of fracture surface, metallographic microstructure analysis and other relative tests. The result shows that the insufficient
modification, the low plasticity which reduces the ability of bearing concussion when riveting of this casting
part are the main causes of cracking. Meanwhile, the pressure produced after the assembling is also the important
cause of riveting crack.