Added pics and specs to CS-90WH Cold Steel War Hammer
The War Hammer- an ideal weapon for use against an opponent who is encased in plate steel. The heavy hammer head could crush the strongest helmet or suit of plate armor with just a few blows and the back spike could rip through helm and plate like a modern can opener! In battle, the hammer side was usually employed first to knock down and stun an enemy. Once he was on the ground, helpless, the hammer was reversed and the back spike was used to punch a hole through the helmet and deliver the coup de grace.
More information here:
http://www.1sks.com/store/cold-steel-90wh-war-hammer.html