Thanks for the clarification, Gou. Nope, definitely not related to Okinawa-te's Sword & Hammer.
Okinawa-te's Sword & Hammer comes from what supposedly happened when Japan subjugated the Okinawans 400 years ago. According to some accounts, not only did the Japanese outlaw weapons, but they outlawed anything that could be used as a weapon, including ordinary knives and tools like hammers. Supposedly, villages had a sort of communal knife and hammer that were chained together and guarded by a soldier, who oversaw the use of these implements. According to the story, Okinawans would steal these tools and use them for self-defense. The first move of the kata is the clasping together of the open left hand (sword) and the right fist (hammer).
Cthulhu