Here is a new purchace for me: a casting sprue for Wu Zhus. When these coins were cast, what was produced was a "tree" of coins with the main channel in the middle and "branches" for each coin, like this one. After the metal cooled, the coins were broken away, leaving just the center sprue. Then the sprue was often scrapped to cyphen the extra metal to cast more coins, making a substantial part of the sprue a rare find. Now, enough waiting and background info. Here is my sprue: And here is my mould for those that might not remember:
Very nice! Cool way to illustrate how the coins were made. Your piece is actually a sprue with runners and would be WIP or Work in Process inventories. It would be remelted into Raw Materials Inventories (bronze). The trunk of that tree would be the Sprue, with the branches to the coins being the Runners. Where the Runner enters the Coin Mold/Mould would be the Gate. The gate on the coin is often filed (trimming process) to smooth out the break from the runner. It is amazing how casting/injection molding/etc. processes are virtually the same as several thousands of years ago.
Nice, not everyday you find a sprue. In case anybody is wondering, thats almost the same way they make jewelry now except the sprue is made with wax.
About those Si Zhu moulds, have you ever questioned their authenticity? I see them all of the time, much more so than actual Si Zhu coins. In addition, several have large dots above and below the hole on the obverse, which I have rarely seen on genuine coins. I am just thinking probabilities, but I was never convinced of their authenticity enough to buy one
LOL not too technical as this is a very low grade technology. I am just parroting how we do it in manufacturing.
I never questioned them. They come from a reputable source. They are about as common as the Wang Mang moulds, roughly.
Fair enough. I have seen the Wang Mang ones as well, but a little less regularly. The shattered Wang Mng moulds make sense because they were destroyed when they were no longer used so that they would not be usable for counterfeiting. I'm guessing the same was happening here, but that makes no sense. The Si Zhu coins were cast at a 4 zhu weight, so counterfeiting would not be profitable, unlike with the Wang Mang coins. That's why intact or relatively intact Wu Zhu moulds are found with some regularity.
