This is a Jerusalem cross. It is really four small crosses and one larger cross for a total of five. I did a similar Instructable quite a few months in the past, but its construction was quite different.
The earlier version involved cutting the nails and brazing the pieces back in place. I wanted to try an all-welded construction. The welds are all done from behind the finished surfaces, except for the weld in the center that is covered with brazing rod for decorative effect.
Click on this link
to see the earlier version and to read about the significance of the Jerusalem cross.