Ha ha, dear Weldman, you pinponted a real interesting and puzzling question which is awful difficult to answer. Sword blades steel are secrets that their makers guard with seven keys.
The art of making swords blades started when the prehistoric man learned how to use iron, it goes back to the Iron Age.
The gladiators of the Roman Empire used swords which were case hardened following methods whose basic principles and procedures, believe it or not, are essencially the same as today's. Romans were wise people, as you see.
Then, in the Middle Age, the swords used by the Arabs, with which they fought their "Holy Wars" in the name of the Prophet and under the sign of the half moon, were made in Toledo, Spain (not Ohio, because in those days America wasn't still discovered).
And what about Excalibur, King Arthur's sword, which was capable of being nailed down into a stone? Can you imagine the material it was made of? The only sword in the world that can be compared with Excalibur is Tizona, the sword of Cid Campeador of Spain, who fought against the Arabs using that invincible weapon.
In my opinion, any answer that you may receive to your question will be just an estimate, or rather, guesstimate. Only the maker knows exactly the steel he used to make the sword. Bear in mind that the chemical composition is the less important thing. The most important is the heat and mechanical treatments it received.
What to do? I don't know about flexibility, but I can give you a clue on the strength. Carry out a hardness test in a competent laboratory. Hardness test is a non destructive one, it's performed on the surface of the blade leaving no visible marks on it. Once you know the BHN (Brinell Hardness Number) of the material, there are tables which indicate the approximate correspondance between BHN and tensile strength. These tables can not be used for exact calculations in engineering projects, but for your case are perfectly OK. If you don't know how to get one, I'll mail a copy to you.
Giovanni S. Crisi
Sao Paulo - Brazil

I have seen knives stamped "surgical steel" and I am pretty sure that surgical stainless steel is that grade which will not corrode in the service conditions expected in medical operations. I think Surgical Steel is probably some 300 series ss.

If a decorative sword were required 300 Series SS would be a very good choice. 300 series cannot be hardened by heat treating but will not rust or corrode in many applications. Early makers of swords for actual use were probably un-concerned with corrosion/pitting as the owners of the swords cared for them on a regular basis.

The ability to maintain an edge, deform without breaking and returning to the original shape would be some key concerns if I had to use a sword. Another concern would be that the length and weight would not hinder me from RUNNING.

Good Day

Gerald Austin
weldinginspectionsvcs.com

There are ways to positively identify the material, but the easiest thing to do is take a magnet to the blade. Check to see if the blade is magnetic, even slightly magnetic. If it truely is entirely non-magnetic, then I agree you are most likely a 300 series stainless. There are, however, several heat hardenable alloys with excellent strength and flexibility, entirely acceptable in medical applications. Greek ascoloy shows up all the time, with excellent corrosion resistance when polished. But, the heat hardening grades are all magnetic to some degree.

Surgical Steel or maybe Chrome plated?

Logically speaking (my logic) few people engage in sword fights any more so the sword in guestion is most apt to be for ornamental purposes.

It would require little maintenance like cleaning off blood and guts or stoneing out nicks from clashing with another swords.

The magnet will tell you if it is indeed Stainless Steel. The 300 series would be best choice for a decorative piece. Like you've been told it is not hardenable, (easly damaged) and no spring quality (will yeld if you bend it) but great tensil strength.

I believe surgical stainless is highly polished 316 CRES. I worked in a sheet metal shop where we made Laboratory countertops and fixtures. It is also, used in food preparation environments. It has something to do with sanitation purposes, whether it's resistant to corrosion from cleaning products or the fact that it is not a porous material i'm not sure.

Of course, the times of Robin Hood and Captain Kidd have long passed. This doesn't mean, however, that swords are used today only for ornamental purposes.
In first place, fencing is a widespread sport in many countries, being even a sport played even at the Olympic games. You can be sure that fencing champions give to their swords the same treatment King Arthur gave to his, and they demand that their swords' quality be not less than Excalibur's.
Secondly, there are the collectors of swords and other weapons. No, they don't use swords for killing people, but you can be also sure that they also demand that the swords of their collections be of top quality. Stamps collectors don't use their stamps to mail letters but they want the best possible quality stamps.
I don't think swords are made of any AISI series 300 stainless steel. Those are austenitic stainless steels, which are not hardenable nor able to be quench and tempered; and we'll all agree that swords must be hardenable and able to be tempered. Do you gentlemen imagine Peter Pan fighting against Captain Hook with a soft sword that bends after 2 minutes?.
Rather, I think that swords are made of some martensitic AISI series 400 stainless steel, such as AISI 410 (chrome content of 12%). Martensite is the metallurgical steel form able to be hardened and tempered.
Now, as I said on my first posting, the chemical composition is the less important thing. The most important is the heat and machanical treatment the blade received, and this is a secret the maker keeps under seven keys. I'd guesstimate that "as rolled" AISI 410 steel has a hardness of, say, 200 Brinell, whereas finished swords must have, say, not less than 500. How do you reach this number by starting form a much lower one? By proper heat and mechanical treatment.
I repeat my first suggestion: measure the blade hardness and then, by means of a table giving the approximate relationship between hardness and tensile strength, figure out this latter one. Again, these tables are only approximate, not to be used for engineering calculations, but for this case are OK.
Giovanni S. Crisi
Sao Paulo - Brazil