Ch'i Type Knife S-45-50.
Obverse: Three characters reading "CH'I FA HUO" which loosely translates to "The authorized currency of Ch'i". The reverse generally has a single character, but there are a number of different types known.
The knife money of the Shantung Peninsula is far less complex than the spade money, but is still poorly understood.
The monetary designation of knife money is "HOU", derived from a character meaning "to change" or "to exchange in trade". It is fairly easy to see how this meaning could become a denomination of money. Later, when the early round coins first appeared, the unit of "HOU" came to be used as a more general denomination.
The large heavy knifes may be the most misunderstood part of this series. In most early references they described as the earliest knife form, going back to before 600 BC, but this seems un-likely as they are a highly evolved form with fairly complex inscriptions, and must actually date very date in the series. In Hartill's book (Cast Chinese Coins) he dates them to between 400 and 220 BC, which makes them fairly late in the knife money series. I personally suspect the dates might even have to be moved up a little on that, which I will discuss below. With the exception of the three-character Ch'i knifes, most heavy knifes are rare to extremely rare.
Knife money is the name of large, cast, bronze, knife-shaped commodity money produced by various governments and kingdoms in what is now known as China, approximately 2500 years ago. Knife money circulated in China between 600 to 200 B.C. during the Zhou dynasty.