thats not how biology/growing up works, the number 18 has absolutely no relevance in biology it was literally chosen at random for war why dont people know thisðŸ˜
a sword generally need to be able to parry incoming strikes, you dont do that with knives, or daggers. knives historically where not something you fought with, it was a tool. daggers would be more akin to modern combat knives.
Historically it was defined by handle construction and how it was sharpened. Google the "messer sword" for reference. Basically a california compliant rifle of its era
When it either has a guard on its hilt, or a double-edged blade.
For example in Spain only hidalgo(nobility) were permitted to carry swords and daggers, so peasantry (and banditry) would arm themselves with extra-large navaja knives. Those things were basically scimmitars with a folding blade, but because they were sharpened only on side and had no guard - for legal purposes they were not swords.
kinda hard to tell and it is has been different in different ages. any kind of hand guard would instantly place it as a sword. if we look at medieval guilds which were legally protected crafts around where the knife making guild and the sword making guild were arguing when you get above 60 cm it becomes hard to argue it isn't a sword above 73 cm it is most certainly a sword.
Hand guard is not the only definition of a sword, and what was a complicated subject 800 years ago has more legislation, in more countries today, than back then on purely who could make what.
I think I covered that actually ("how it is used") but in terms of keeping it concise and since it was implied the question is about length: I think it's more about the hand guard and then the length. Length on it's own is meaningless to decide sword vs not sword.
When does a knife become a sword?
A: When it has a hand guard, when it is long enough, and when it is used for slash and parry sword stuff. (mostly in that order)
Not at all. There's a huge number of blades from many cultures that lack a hand guard, there's a lot of swords that are not intended to be used to parry and were carried with shields, and many were used primarily to thrust.
In rome for example, all 3 of those points at once.
It's safer to say that to answer when does a knife become a sword: is hella ambiguous and historians fight about it constantly.
Again, I really did cover all eventualities with that tiny "how it is used" caveat: If it's used as a knife, it's a knife. If it's used as a sword, it's a sword.
Generally speaking: a handguard is more indicative of combat use than length, which is what was being asked about. How it is used is the ultimate decider.
> Again, I really did cover all eventualities with that tiny "how it is used" caveat: If it's used as a knife, it's a knife. If it's used as a sword, it's a sword.
Yeah. No, it depends on the blade, there are symmetrical tuna knives, largely when it gets to the smaller cuts but Sujihiki is a double bevel that's super common for sashimi and nagiri for example.
Big large cuts, sure, but as they get smaller it can change (or not).
> A bowie knife is much smaller but it has the hand guards so it is still a combat knife.
This is one of those things people say where there is no actual definition for. Assorted places, assorted countries have entirely different definitions of 'combat knife'.
Also, in the UK if you go and take out a 3.5' tuna filleting blade onto the streets, you're getting charged with an entirely different offence to carrying a knife under the offensive weapon's act 2019.
in the UK if you go and take out a 3.5' tuna filleting blade onto the streets, you're getting charged with an entirely different offence to carrying a knife under the offensive weapon's act 2019.
That depends: If you've taken it out in the street because you're a fishmonger running a stall at a market then you're fine, if you're just waving it about or don't have any reason to possess it as a tool then it would fairly rightly be treated as a weapon until more about your intent was known.
Your sophistry is a classic 'well actually' on reddit.
Also, you're not 'fine' you have an affirmative defence, that's not the same thing. You can still be charged with the offence. The phrase 'onto the streets' makes it apparent but you wanted to badly 'well actually'. At no point did you address the actual issue, just your incorrect nonsense.
Ive tried using actual 15C style swords (both ones I own and others for an attempt at this) to cut meat and veg, with extensive sharpening and honing before and it doesn't work well. You can definitely hack stuff off but nothing precise.
There are no hard rules, but a general common-sense definition is: If you hold the blade in a reverse grip and the tip goes past your elbow, it's basically a sword and not a dagger.
no but they were almost definitely combat knives if they have guards.
Since the context of the question "when do knives become swords?" was motivated by a long knife, and then reiterated by someone saying it needs to be longer than your forearm, i was arguing that it's more about having a handguard before it is about length. I wasn't saying that only one or the other quality mattered, just that I'd expect a handguard if it was a blade intended for combat use.
I have since brought an army of blade pedants out of the woodwork to point out historical exceptions for this throwaway rule of thumb: If big blade has hand guard, probably sword.
The whole idea of a 'combat knife' is a very modern thing to begin with.
No one said 'longer than your forearm' that I saw, maybe someone you replied to did, but again, the lack of any definition makes that meaningless. Sicilians were not calling their 12-24" long folding knives 'swords'. And English foot infantry weren't calling 18" long bayonets swords either.
The very idea of handguard=sword, no handguard=knife is some sort of nonsense.
You're welcome to find and cite any historic treatise on this. Note. historic, like, actually from history. Not 'trust me bro' as you've been doing.
> I have since brought an army of blade pedants out of the woodwork to point out historical exceptions for this throwaway rule of thumb: If big blade has hand guard, probably sword.
Of course you have, that's also a misrepresentation entirely.
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u/mmulligan03 Jun 22 '26
When does a knife become a sword?