Sledge Hammer

One of man's earliest tools, the sledge hammer is used for driving stakes, destruction, and influencing motion of large objects by imparting concentrated energy. They come in a variety of weights. The one Norm used is not discernible as to weight or brand. It also had the appearance of a tool that has been in inventory for quite a while.

I think I've only seen the one appearance where it was used to drive stakes of rebar through the foundation beams of the greenhouse.