By the term "replica sword" I am referring to the "wall-hanger" class of cheap swords made of Stainless Steel.

Can these be considered as actual weapons? Yes, in that if you conceal it in your trench coat, you might get arrested for concealment of an illegal-length weapon - regardless of how authentic to traditional sword manufacture your sword is.

In the classic sense, the answer is no. As discussed in other section articles, stainless steel contains chromium. This gives the resultant blade a nice chrome look. However, chromium makes the steel molecularly weak, and thus the sword is vulerable to deep scratches and a damageable edge - and more. Thus, manufacturers of replica swords compensate by making the swords thicker. Now, thicker also means heavier.

On the battlefield, a heavy sword is inefficient, will weigh you down, will make you tired, and get you killed.

Can you kill with a stainless steel sword? Yes, naturally. It can be used as a stabbing weapon and, to an extent, a cutting weapon, depending on its edge. Because these swords are not heat-treated in the traditional manner, the edge will not retain sharpness after you cut cardboard several times. Traditional Japanese swords can cut through bone and still retain its edge!

Remember that Japanese swords, specifically, are not chopping weapons, as opposed to what you see on TV. The Japanese sword is good for piercing, but its ultimate edge (no pun intended) is in its ability to cut. Japanese swords feature edges with extremely high Rockwell hardness for cutting ability and a lower Rockwell hardness for its spine for impact absorbtion and toughness.