Quality of an antique sword blade?

[bond_fan]

How does one tell if the blade of an antique sword is well made if you're not going to cut rattan or bambo with it??

Same question for new blades?

Also, how do you tell if the blade has been acid treated to make it look like Damascus steel?

Thanks!

[Peter Dekker]

How does one tell if the blade of an antique sword is well made if you're not going to cut rattan or bambo with it??

When judging an old sword there are two things to take into consideration: quality and condition. A well made blade might be in very bad condition while a mediocre blade might be in excellent condition.

Things to look at when judging old steel are: stress cracks (little hair cracks in the hardened edge), significant nicks, pitting, straightness of facet lines / fullers (if any), and temper. To test a sword's temper you hold it upright with the blade up and hit your hand with the other. This will cause a vibration in the steel. When steel is tired due to excessive loss of thickness in various polishes or due to excessive heat, the blade wobbles a bit and feels "dead". When it is resilient and feels alive, it means you have pretty good steel.

There's no real way of explaining all this without looking at a fair amount of antiques. Once you've held a number of them, you will develop a pretty good idea of which ones are good and which ones aren't.

You'll probably never 100% know whether an antique is structurally sound enough for cutting without doing tests that might possibly damage it. In my view there is little need to put an old sword through such tests, it is better left as is for form practise or to appreciate as a piece of history.

On new swords things to consider are:

-How safe is the hilt constructed
-How is the weight, balance and how does it play
-How is the temper
-What hardnesses do the various parts of the blade have
-What is the blade's cross section like

Also, how do you tell if the blade has been acid treated to make it look like Damascus steel?

Monosteel that is etched as to look like folded (damascus) steel generally has very course lines that sharply contrast with the rest of the steel, as opposed to the majority of real folded swords that have a more subdued pattern. There are exceptions to the rule: some folded steel is actually acid treated to bring out the details of the steel more, like Indonesian Keris. Folded steel is widely used for badly made reproductions as well, so whether or not a sword is actually forge folded or not doesn't necessarily say much about the quality.

-Peter

[Chris Fields]

another way to test a swords temper, is to hold it a few inches higher, but parallel with a table or the floor. Let the tip drop to the surface and it should bouce several times, each time the bounce should be only slightly smaller than the last. A good temper sword will bounce 5 to 7 times. A poorly tempered sword will bounce once or twice and then stop.

Remember to use a surface that is firm enough for the blade to bounce, but will not scratch your blade. Like a towel over a counter top or wood floor.

This is also hard to do with a curved sword. =)

[Peter Dekker]

another way to test a swords temper, is to hold it a few inches higher, but parallel with a table or the floor. Let the tip drop to the surface and it should bouce several times, each time the bounce should be only slightly smaller than the last. A good temper sword will bounce 5 to 7 times. A poorly tempered sword will bounce once or twice and then stop.

Interesting method! I tried but found that with the best of tempered straightswords I have (some antique jian) each bounce is not slightly smaller than the last but rather erratic because the whole sword vibrates a lot between bouncing after it came down the first time.

Also, when testing the temper in the hand you pick up a lot more info through the hand and the eye (as watching the center of percussion) than can be obtained through this method.

I don't exclude that it might be a perfectly good method to test the more modern tempers with, as they are generally a bit less resilient than these old Chinese swords are.

-Peter

[Chris Fields]

Yeah, I have only used this on modern swords personally.

The technique was shown to me by a master knife maker in Tallahase Fl. Edgar Chattan was his name, he's had alot of articles written about him knife magazine and such in the past. He is retired now. I spent a few summers with him about 5 to 6 years ago, learning how to forge and build knives and swords. He would use this technique to check each of knives and the few swords he made when I was there.

[Chris Fields]

Oh, tried this with my Huanuo Oxtail Dao, and it worked great, good temper, got about 5 or 6 bounces.

On curved swords, you have to grip around the entire circumference of the guard so that the blade doesn't twist when the tip hits the surface.

Again, this a modern mono steel sword though.

[Philip Tom]

The "bounce test" is interesting, and can be a valid way of checking the temper (resilience) of a blade. However, there are some factors that may affect the results:

1. Distal taper. A blade that changes considerably in thickness from forte to tip should bounce more than a thick, stiff one with comparatively less distal taper. I don't have a katana handy, but those of you who do might want to try the test with such a blade (especially the heavy, World War II-vintage ones).

2. Curve. It's a problem getting strongly curved blades to cooperate in this test. I just tried it with a late 18th cent. Ottoman shamshir with a Persian blade that's both stiff and deeply curved. Couldn't do the test at all, the blade wants to twist and impact the table top edge-first.

The method should work beautifully for jian blades, though!

[HomoCaballus]

Letting a blade bounce like described provides information about flexibility/stiffness and hardness but also about blade harmonics.
It is a bit tricky too as the hardness of the surface will greatly influence the bouncing, just like a hard sword will give a more ‘musical’ sound when tapped, yet hardness is as we all know a pitfall.

This sound note brings us to swords harmonics.
Swords harmonics is the way (shock)waves behave in the blade, the frequency and node placements.
A good sword will give the least shock in the grip.
The centre of percussion is one piece of information more about the geometrics and behaviour of a sword.

Two informative articles about this are:

http://tinkerswords.com/Harmonics.html

http://www.albion-swords.com/articles/i ... namics.pdf

It is clear that the hilt MUST be seen as an integral part of the sword.
What is also clear is that the location of the centre of percussion will greatly determain the way the sword will bounce.

You can try to figure the harmonics out for a sword by tapping it on something solid starting from the tip and working op the blade.
Another method is to hit the tip while holding the grip firmly and let the sword vibrate a surface with contrasting particles in the hope a wave patter will form. This will represent what happens in the blade.

Hope this helps.

petrus