# Communities > Antique Arms & Armour Community > Chinese, South-East Asia (CSEA) >  Reproduction project of a bronze Han dao

## Jeroen Zuiderwijk

Since early this year I've started preparing to reproduce the ancestor of all daos and katanas: an early Han dynasty bronze dao. Information on these swords is hard to come by, but I feel I've got sufficient information to at least make a decent reproduction. Below you can see an original, on which my reproduction will be based:



Some general information regarding these swords:
Before the Han period, only double edged swords were in use in China. In the Spring and Autumn and Warring States periods, these were generally quite short, ranging in size between 40-60cm incl. hilt. At the end of the Warring States period, and particularly in the Qin Dynasty, they drastically grew in length to 80+ cm. Although iron has occasionally been used in swords since the Spring and Autumn period, bronze dominated by far. The bronze used in China was quite different from other bronze age cultures, due to the much higher tin contents. In Chinese swords, 17-21% tin is generally used, whereas other cultures prefered an average of 10-12%. The result of this is that Chinese bronze is much harder in cast condition, and also much more brittle. Although other cultures workhardened the edges to give a better edge, Chinese bronze allows a much sharper edge (easily sharp enough to shave with). The downside is that rather then bending, Chinese bronze breaks instantly if overstressed, though it gives quite a bit of flex to the swords if long and thin enough.

With the start of the Han Dynasty, single edged swords came in use alongside the double edged jians. The earliest ones were made in bronze, and copy much of the earlier jians. The double fullers remind of the octagonal cross-sections of the earlier bronze jians:



Although earlier bronze daos exist, these were just short knives. The Han daos are full length swords, at 90cm. Unique for these daos are the ring shaped pommels, as well as the introduction of the habaki. Bronze daos seem to have been replaced quickly be steel ones, as they are very rare (I only know of 4 examples so far). The sudden phase out of bronze is quite interesting, considering iron had been around for centuries before. It may be possible that at that point hardening became well understood, and they were able to make swords with hard edges, but without the brittleness of the bronze, making bronze suddenly obsolete. Interesting though is that China was the last bronze age culture (aside from the Incas) to produce bronze swords and other tools. Bronze daos did not disappear completely though. A much thinner, and shorter (roughly 70cm, some shorter) single fullered variant was produced in fairly large numbers. These however were probably not functional, both due to the thin, weak blades, and that they weren't sharpened AFAIK. 

For more information, check this excellent website:
http://thomaschen.freewebspace.com

----------


## Jeroen Zuiderwijk

Last winter, I prepared models for the blade:



pommel:


habaki:


and the guard:

----------


## Jeroen Zuiderwijk

Over the last months, I've done 4 attempts to cast the blades, of which three can be seen below. The first was in lower tin bronze (12% tin), before I found out more about Chinese alloys. The second attempt I tried to cast a blade in Chinese alloy, but as the bronze was so thin, it ran straight through the mould. The third attempt is in the middle. Again with Chinese bronze, and this time a seal in the mould. This worked, though the mould had too large a gap due to the seal, causing thick flash, and an overweight blade. So that one will be ised to do some experimenting with the strength of the bronze. The third (low) was the best so far. It's still a little on the heavy side (~1000grams) and the blade is a little curved. This can't be straigthened cold, as the bronze is too brittle. But I've found that this alloy can be hot worked between roughly 600-800C (whereas that's impossible with regular bronze, which is redshort).

----------


## Jeroen Zuiderwijk

I've also cast the first habaki and pommel. They came out quite nice, but after some rough grinding, I noticed a fair bit of small bubbles in the metal from (gass from the mould). So I'll reject those when I cast better ones.

----------


## kevin.feng

here is a reference....  :Smilie: 

http://bbs.hl365.net/viewthread.php?...386&highlight=

----------


## Jeroen Zuiderwijk

> here is a reference.... 
> 
> http://bbs.hl365.net/viewthread.php?...386&highlight=


Thanks! Interesting to see a double fullered iron example as well. And another view of the one I'm reproducting. I'm assuming that the diagonal lines on the grip are remains of the original covering.

----------


## william.m

Amazing work Jeroen. I have always loved these bronze han swords and to see you reproducing one is fantastic!!!

----------


## Mat Rous

You have been busy Jeroen! 

I love your modelling. It's great to see these blades from start to finish. Nice background as well as I hadn't seen this type before.

----------


## Ruud B

Hi Jeroen,
Are you sure the gas bubles are from the mold? looks to me like it was casted to quick. Preheat the mold and cast a bit slower and you should be good.

----------


## Jeroen Zuiderwijk

> Hi Jeroen,
> Are you sure the gas bubles are from the mold?


Yes, pretty sure. I've seen this frequent enough to recognize it. I know some ways to limit the chance that it can occur, one of which I'd forgotten.




> looks to me like it was casted to quick. Preheat the mold and cast a bit slower and you should be good.


 This type of mold can not be preheated, nor can I cast any slower, or either the bronze solidifies, or is just too cold to cast (causing shrinkage porosity, folds etc.).

----------


## kevin.feng

[QUOTE=Jeroen Zuiderwijk;1045056]I've also cast the first habaki and pommel..... QUOTE]

what a fantastic DIY! I would recommend to fine-tune the model a little bit. Here is a typical model.

http://bbs.hl365.net/viewthread.php?...FA%B5%B6%CD%F5

----------

