I was looking through movie memorabilia and came across a site selling movie swords, made in China and of stainless steel. Now, these obviously wouldn’t last against a modern real sword (I’ve been to the Wilkinson Sword factory and seen the real thing made) and are really only good for display or stage. Being steel, they’d easily best a bronze sword, so I wonder how far back in time you’d have to go for one of these replicas to be comparable to a decently forged sword of the era?
Stainless steel swords are, for the most part, only wall hangers.
They are not fit for any sort of martial use (training in a historicla martial arts). They are not fit to be used in test cutting (if sharp, which they rarely are). And most are not fit even to be swang around in the air (due to poor tang construction).
The factors that determine the performance of a sword are many and include: Blade geometry (distal and profile tapering, risers, fullers, tang quality, harmonics, pivot points, point of balance, center of percussion, etc), edge geometry (secondary, primary bevels, etc), material used, hardening and tempering, fittings contruction (the crossguard, handle and pommel).
Changes in any of these factors will change how the sword performs and it’s intended use. Is it a cutter? Is it a thruster? How does it perform each of those functions? Will it stand up to armor combat (is it a war sword?), or will it perform better against softer targets?
Most stainless steel swords do not have a proper tang, they are not properly heat treated, and most will have absolutely no consideration for proper blade geometry, weight, or balance.
Creating a proper stainless steel sword IS possible using modern metallurgical science, but a properly made one will run you in the several thousand dollar range (due to the special considerations including the difficulty of applying a proper heat treatment), for something that will have no advantages (even some disadvantages) compared to high carbon steel sword (and a very good modern, high carbon replica will run you considerbaly less than that typically).
A modern stainless steel wallhanger would likely get a medieval smith a slap on the head 
I agree with everything that Kinthalis posted, except that the heat treating costs wouldn’t be quite so high (at least we didn’t pay a heckuvalot where I worked for heat treatments). And if you have any doubts as to the “quality” of a stainless steel sword, then I suggest you check out this video clip of a QVC demonstration of one. :eek: 
Tuckerfan My understanding from smiths who have worked stainless steel blades (and there are few indeed!) have all mentioned the difficulty in applying a proper heat treat for a sword that will be both springy enough for rugged use and hard enough to hold a good edge. This was a while ago though, things might be different now.
Well, to be fair, my experience is with industrial applications, and even though these included blades (for automated chicken gutting machines) they weren’t intended for the kind of abuse that a sword could be expected to withstand in combat, so that might account for the difference in price.
Interesting clip. I note that the tester is bashing the flat of the blade on the table. This is not good with that sort of sword anyway - the strength of katanas is along the other two axes. A bronze sword would simply bend, as might a poor iron sword.
Anyway, as I noted in my OP, we’re agreed that they’re not much cop compared to the real thing. The question is how far back do we have to go to a time where they would be?
I’d doubt that they’d ever be comparable, since a good, heavy iron sword would probably make mincemeat out of the thing. Remember, the guys making swords were concerned about the user being able to stay alive, while a crappy Chinese knock-off of Mel Gibsons Braveheart sword is being made to look pretty and that’s it. A bonze sword might even be able to do one in, depending upon how well they were made. About the only advantage I can ever see of a SS sword having over an iron or steel sword of any era is if you’re stuck fighting a long campaign in a swamp, somewhere.
They make great shisk kabob skewers!! 
Possibly never. The sword in Tuckerfan’s clip is brittle as hell. Old wrought iron swords such as those used by the Celts against the Romans were soft but tough - they’d never break like the one in the clip, and ditto for a bronze sword. I don’t think there’s ever been a period in history where brittle swords were used as weapons - they’re just not practical.
“Stainless steel” is a bit of a blanket term for a whole family of alloys with rather different properties. The 13-chrome stainless originally concieved for cutlery might make a poor sword, but as good as a Celtic iron sword. Grade 304 (used to be known as 18-10 in the UK) is also used for cutlery, among other things. Normally it’s soft, but it is work-hardened considerably by cold-rolling for such applications as stainless wire ropes or bolts. A work-hardened 304 blade would beat a bronze sword or Celtic iron sword, but would still be lousy compared to a katana.
There’s a family of stainless steels that are “precipitation hardenable” the “PH” grades. (Grades 15-5PH, 17-4PH, and 17-7PH are the most common.) They contain copper and can be heat-treated in a manner similar to carbon steels, although the mechanism is quite different. When heated red hot (“solutionised”) and allowed to cool, they are soft. When reheated to a lower temperature and held there for a time (“aged”), they get progressively harder, reach a peak and then get progressively softer with time. The peak hardness can be impressive.
A blade of 17-4PH could be solutionised, cooled and part-aged. Then just the cutting edge could be re-solutionised with a fast pass of an oxy-acetylene flame, or by induction heating. Aging the solutionised cutting edge to peak hardness would over-age the rest of the blade, giving a hard edge and a springy back. It’s not a job a blacksmith could do and it would cost a fortune, but you could make a stainless blade as good as a katana.
And that’s the sort of answer I was seeking.
Hang on, a second there, bub. While matt’s right that a 304 blade could probably make short work of one bronze or Celtic sword, it wouldn’t have the life expectancy of either of those two swords. With 304, work hardening isn’t something you can turn on and off with a switch, so while you could hack a Celtic or bronze sword to pieces with it the first time, you’re going to harden your blade just a bit, and put it at risk for fracture. So at the end of the day, you might end up with a broken sword, while the guy with the Celtic sword, who’s managed to avoid you until this moment, shows up with his battered, but still functional weapon. :eek:
What exactly is meant by “beating another sword”? Swords are not crashed into eachother edge on edge as is portayed in movies. When properly used a migration era pattern welded sword will perform just as it was meant to against say a later medieval arming sword.
Oh, and I should point out from personal experience that 304 work hardens easily, to the point where most modern machine tools are useless to try and machine it. A good primer on stainless steels can be found here. Another thing that that article points out, is that when 300 series gets work hardened
So you might wind up with a giant sword attracting magnet!
You know, I’ve heard that, but I’ve never seen an explaination of what one is supposed to do in a swordfight, if not swing your weapon to block your opponent’s blade.
The prefered method of dealing with incoming attacks are by voiding either by outiming your opponent or through footwork, setting aside the blow with oposition (hitting the opponent whilst covering his attack), or setting aside the attack while threatening with the point or edge (parry and riposte).
Parries are done with the flat of the sword preferably, or with the edge on the flat of the opponent’s sword, or with the edge at an angle to the opponent’s edge although almost always on the strong of the blade near the crossguard.
And never is it a static, 90 degree, edge on edge BLOCK as seen in movies and re-enactment. It just doesn’t work, and it’s hell on your sword 
Very good question! I think we’re talking about superior in mechanical properties. E.g. if you had two swords of identical shape and balance, but one is mild steel and one is spring steel, the spring steel sword will keep its shape and hold a better edge. Doesn’t mean to say that someone with the spring steel sword would beat someone with the mild steel sword in combat. I’m pretty sure a decent fencer armed with a broomhandle would take me down armed with a lightsaber, if he had room to move around.
Also, to an extend “good enough” is good enough. A case-hardened 4320 alloy steel katana may be superior to a traditional katana on paper (harder edge, higher yield point, greater toughness) but if there’s no difference in practice, who cares?
I think “useless” is a little strong, although it’s certainly a pain in the arse and you have to cut slow. Our workshop turns, mills and bandsaws 304 fairly frequently. They do grouch about it.
If you want something that’s really a pain to machine, try maraging steel. Or better yet, tungsten carbide.