The weight of the swords

[Pierre F]

Hello everyone,

 

I was wondering if by any chance some of you would have answers to the questions I have about the weight of swords.

 

Indeed, I note considerable differences in weight between swords of similar shape and length.

 

I seem to notice that the older swords (13xx and before) seem to weigh less than the more recent swords (1800 and later).

-Would you know if it is the steels used that can explain this ?

or

-if it is the successive polishing that can explain the loss of 30% or more of the weight of a sword (again on very similar dimensions).

 

Or more simply my "observations" are wrong and there are for example 13xx swords of 70 cm that weigh in the 800 grams...

 

I'm sorry by advance for this question ...  thank you by advance the good soul who could take time to read and eventually... answer my question.

 

Thanks ;P...

[Lewis B]

IMHO differences are due to the geometry of the blade in question. It has nothing to do with the steels used in different eras per se. Neither does the forge welding and folding have any noticeable effect. My Shikkake from the late Kamakura, early Nanbokucho era is 70.6cm, motohaba >3cm and weighs 770g. No Hi. The Senjuin is a lot more diminutive at 62cm and 2.55cm motohaba, 1.65cm sakihaba but with >7mm wide shinogisuji and full niku. Even with bohi the blade weighs 450g. Put them side by side and the size differences are dramatic.

[Benjamin]

E=mc² so m=E/c² so the more the smith put energy and dedication to his work, the more the blade is heavy .. 

 

Joke appart, I think that's a matter of volume (thick blades) and density.

I imagine that the smithing lamination technique  wich use repeated hammering will crush the steel and increase it density. The more a blade as fold, the more it would be heavy at same volume.

Just deduction, I haven't source to say that, let others correct me if I'm wrong.

 

But if my hypothesis is right, nashiji or koitame hada would create heavier blade than oitame hada.

[Michaelr]

Just my two cents here. Different smith, different blades. Different times, different shape, different designs may ALL lead to Different Weights. I have always been told to take the sword in hand and hold it out, no matter what the weight it should feel balanced. I have held both light blades and very heavy blades and if they don’t balance you feel it right away. I know this doesn’t necessarily answer your question but like I said just my two cents. Look forward to more answers.   MikeR

[ROKUJURO]

29 minutes ago, Benjamin said:

....I imagine that the smithing lamination technique  which uses repeated hammering will crush the steel and increase its density. The more a blade is folded, the more it would be heavy at same volume.....

Benjamin,

you cannot increase the density of a metal with mechanical methods. The density of steel is always 7,85, and very small variation would only be possible by using special alloying metals like tungsten or cobalt. In theory, large quantities of a lighter metal like titanium would make the steel less dense, but that would show only in the last figures. 

Just to mention it, intense hammering does not make the steel harder....

[Benjamin]

Thanks for the correction Jean, I learned something

[Pierre F]

Thank you LewisB, Benjamin, Michael, Jean, Benjamin... for your answers.

 

I learn from your answers ;P

 

 

 

 

 

[Jacques D.]

The mass of the steel remains the same, but the weight of a sword depends on its sugata and the number of polishings it has received; thickening stones have not yet been invented.

[2devnul]

19 hours ago, Jacques D. said:

number of polishings it has received;

 

I must agree with @Jacques D. here, that is probably the reason why you see older blades weight less. I'm not talking here about balance or 'how do you feel the sword'. I'm talking here about pure weight in grams. 

 

IMO answer is simple, older swords were polished more times then the younger blades = less steel = less weight. 

I don't think that blacksmith skill/style or type of steel (if we talk here only about high carbon steel, not titanium etc.) makes any differences. 

 

Again, if you want to compare blades, you need to make sure that Sugata, Bo-hi, Moto/Saki-haba etc... is the same (impossible, as every sword is different) or very similar. 

[Graybadger]

It may be relevant that the Mongol invasions of Japan in 1274 and 1281 revealed the need for more robust swords. I read somewhere that thin tachi blades would stick in the boiled leather armor of the Mongols. Subsequent study of bent and broken blades by swordsmiths resulted in a movement to heavier blades.