Pointless technical information about blades: Damascus blades (which would have been well known in northern legends. cf. Varangian Guard) and Japanese blades were made in much the same way. A differential tempering method allowed the edge to be made of the hardest steel possible while the body was of a softer, more flexible composition. As long as the edge hit another piece of metal square on, it might cut it without shattering. A glancing blow would ruin it. During WW II, the Japanese army used the Mountain Hag Cutter sword to cut the barrel off a Nambu Light Machine Gun. The sword is still here. I've seen it.

Note: The Japanese tried making swords out of blocks of softer and harder steels welded in a sandwich style structure. They tended to come apart.