In one book there was monomolecular blade that was supposed to be sharpened by a power hungry force field which is eating away at the blade. Thus if you blunt your blade enough to lose effectiveness you push a button, and field shave away some of the blade
I feel that most futuristic ultra-sharp swords would realistically go in this direction - instead of settling for a blade that cuts okay and stays sharp, just make incredible blades that dull or break in one or two cuts and find a very efficient way of either re-sharpening or replacing them mid-combat.
@@WhatIsThatThingDoing Sure, but... the scientific meaning of "solid energy" is very vague. And will probably never be a thing. Energy itself doesn't actually exist - it's just a theory that we use to describe how matter changes and where the... well, *energy*, comes from during these changes. With that said, in the far, far future, let's assume that we learn how to out-right prevent all energy transactions on certain matter. With this tech-wizardry, we could then freeze the energy of a metal, essentially preventing it from changing, and use it to create a Solid-Energy Blade. It would not chip and it would not break, and these two abilities together would let you make the blade about as narrow as you'd like. This is my interpretation of what this term would mean in real-life (psuedo)physics, and it's probably the best blade you could theoretically make while staying arguably true to what we know about the world. With that said, the elephant in the room is if we will ever be able to screw around with energy itself on such a fundamental level... and I doubt it. And if we ever do... most weapon concepts we know of right now will probably be out of fashion.
@@WhatIsThatThingDoing really depends on the exact mechaincs of the device, for example in the book from which I described the blade the field was to powerhungry to feasibly provide it with enough juice for more than ~a minute of function while keeping it somewhat reasonably sized
I like the drawn examples, helps get the point across further with an image to look at. However the drawings are quite hard to see on a phone screen. Might I suggest a fine liner? Or maybe a whiteboard? These in-depth discussions are great, one of the more enjoyable vids in my opinion, great work! Also that thumbnail is brilliant
"Sharpness is the best thing since sliced bread" hah. It's surprisingly logical, first they discovered sharpness, amazing! Then they discovered they can use sharpness to slice bread, better!
Or enhanced the drawing in post, current edit was basically light grey on shiny white, ideally, drawings on screen should approach a 100% black to white ratio out of the full dynamic range of the screen.
"The sharpest edge is this!" Holds up visably blank page :woah, the sharpest edge is no edge, he's speaking in koans: Turns page, drawing faintly appearant 😑 Jokes aside, maybe use power point slides, I get why you went with this approach, but I couldn't see the demonstration 3/4 of the time. Non the less, love your work
It's not bad on a properly balanced screen, but a lot of gamers increase their gamma so they can see things in deep dark dungeons and other dank places, and loose thier upper color gamut. Could also be hard to see on a cellphone for resolution reasons
@@nosajimiki5885 1080p tv, balanced by my lady for watching hockey, but thank you for letting me know it's visible on some screens, i was curious as he seems to check the screen several times
@@Liminallunatic TVs are usually set up to maximize contrast more than computer screens because it makes otherwise drab video look more stunning. This usually results in loosing out on both the upper and lower most ranges of your brightness gamut. Since Skallagrim is doing video editing, he probably goes in on a semi-regular basis to reballence his monitors, otherwise his hue balance can shift over time making his videos look fine on his screen, but blue, green, or pink on other people's screens... the issue is that this usually means that content creators work in ideal environments allowing them to see those very upper and lower contrasts that get lost on other devices.
Me: "Should I watch the Skallagrim video first this morning, or one of the others in my sub list?" Skal: *Makes a TMNT2 reference in the thumbnail* Me: "Cowabunga it is"
My absolute favourite representation of this concept are scanning electron microscope images of the tips of clinical grade needles, they are nearly *perfect* when brand new, and after a single injection the tip is visibly squished, the hole it leaves after the injection is barely bigger than the needle itself and, obviously, it pierces with next to no resistance at all
Great video and title. I hate when I hear men tell younger guys or women they wouldn't understand. This is very educational and you know very well what you are talking about. Thanks for this video sent it to alot of friends to show them. Scandi is the most useful to me.
On topic of edge roll: In CNC metal working one very important thing is how thick of a shaving the tool produces. The reason for it is that the material itself keeps the cutting edge of the tool from rolling or otherwise deforming. It is weird how you can use a lower-quality cutting tool and completely destroy the edge by trying to go easy on it, yet get great results while pushing it harder. If not enough material is removed, the cutting edge either bends or breaks outward, in the direction that the shaving is coming off at. With deeper cut there is enough material on either side of the edge to prevent this. Not only that, but thicker shavings carry off a LOT of heat that's produced during cutting so the part and the tool stay cooler, which also helps with longevity. This is very similar to why it's so easy to dull a drill bit with a hand drill. Go a bit too quick on the RPM without enough down pressure and the bit will dull in seconds. Put the same bit in a drill press that turns slower and produces about four times the down pressure and the bit will last for a long time. This doesn't really apply to swords and such, but still is IMO a nifty tid-bit that goes somewhat against what you'd expect.
Fun fact regarding convex edges--they are actually essentially the same as a V-style edge of equal edge angle, but with the shoulder removed. Contrary to what many think, the intersection of two arcs does have an angle to it, and while it's possible to have a convex edge that's thicker than a V-grind, it's because it's a thicker angle at the apex! However, the shoulder of the convex with an equal edge angle to the V-grind will go further back on the blade. When drawing comparisons very often people make the mistake of holding the shoulder depth as fixed, which makes convex the thickest possible geometry to "connect the dots" but that's not how it works in real life when applying an edge to a tool, and so the real advantage of a convex is that it allows you to thin the geometry behind the edge without sacrificing edge stability at the apex, and so it will be a little more penetrating than a V-grind of equal edge angle.
Things like the edge being aligned straight, high coefficient of friction/some amount of micro-jaggedness (being too smooth may cause it to slide and roll the edge in, making it blunter. Cutting involves dragging and tearing...) having thin enough a contact cross section to raise applied pressure, being hard enough but not too hard it’s brittle, being enough resistant to elastic deformation, having a favorable weight distribution, blade geometry/edge tappering and blade wideness.
Just realized: This pandemic has now lasted long enough that I have your length hair and I imagine roughly your amount of swords (apparently pandemics awaken the collector in me).
A sword seller I met at a ren faire tried to use a misinterpretation of this to justify why the entirely blunt sword I was looking at was actually sharpened...lmao
I found a book called The Razor Edge Book of Sharpening by John Juranitch a helpful expansion on a lot of this discussion. They even did "clinical trials" with different steel. I think it was a poltry processing facility where people are using knives all day every day as a job. Great video thanks!
so part of my bg is in the world of cnc machining. it was explained to me that the radius of the carbides we used basically concentrated the pressure down to such a small area that the heat generated formed a plasma which is what did the actual cutting. id think that a mega damage entity would be capable of generating such forces on nearly anything with a bit of a taper to it. hell when i got my logsplitter it had a rounded edge but after the first few pieces the pressure had honed that into a near razor edge.
Something I haven't seen mentioned anywhere so far is the concept of self-sharpening blades. It would be very similar to rat teeth in nature: There are two layers, stacked next to each other in two sheats. One is softer than the other, gets abraded more quickly, and so the edge gets thinner, only the hard layer remains at the top, and can then be worn down in turn.
Good amount of information there, even if you're not actually have anything to do with real swords. As a craftsman (wood and metalworking) i really appreciate all the info.
I read somewhere that the only material that produces a radius that is as close to 0 as possible is obsidian, specifically the edges of an obsidian flake. Obsidian is probably the only thing hard enough to sustain that edge, but it really cannot do much, as it's quite brittle because of the hardness.... On the subject of sharpness, when I was an apprentice carpenter the master carpenter spent an afternoon teaching me honing and sharpening skills. I managed to get a chisel sharp enough that it actually managed to get stuck in concrete... But only once, as when I removed it, the tip was pretty much ruined. Like you say, getting things sharp isn't the issue, having a material that's strong enough so it can stay that sharp despite wear and tear is.
Thank you for this video! Usually when I sharpen a sword myself it's sharp enough to cut paper and does well against bamboo... But very often against two liter Coke bottles doesn't do well. I choose to put a more durable Edge because for years my primary test cutting target has been bamboo in the Bamboo Grove near my house. Bamboo supposed to be similar to bone and from the pork I have cut on I agree that fresh bamboo is very much like cutting bone that is fresh. But Coke bottles take a much finer Edge to cut well then bamboo or meat. My edges that will cut bamboo and meat well also can be whacked on thin frying pans without taking any Edge rolling or chipping. But again they're no good for cutting on two liter bottles which is a good backyard fun thing to do. My edges would be able to hit against shield and armor well, but surprisingly not many modern targets
The next video in my notification list includes a hydraulic press. There you can see sharpening a blade is not needed to make it cut if you have a bit more force behind it. 100 tons are sufficient for most cutting needs.
Good video. I was wondering if you might follow up with something about differential hardening and the impact on edge retention. The type of steel and how it is hardened at the leading edge matters a lot. I found that if you use something like O1 tool steel you can heat the cutting edge with like a map torch to cherry red (whole thing needs some heating) and quench it then file to a pretty formidable edge, then the hardening gradient gives you strength away from the lead edge. I made a 90cm single edge blade with 8mm thick back edge 40mm blade width and a convex bevel. It was ludicrously sharp but was able to cut wood and leather easily. I tried this with similar dimension 1095 and it completely went to hell, blade cracked. Love the videos, understanding blade cross sections are a kind of an obsession for me at the moment.
A good way of imagining how something really sharp will break is Obsidian, which is the sharpest thing we know. It can cut hard, but it won't survive the first strike, and that if it is a dagger, any bigger and it breaks under its own weight.
Skall, or anyone who is able to help, I have a question. Why does a slice cuts but if I press the blade straight against a surface it is less effective? I don't understand why is this so, if someone could explain I would be very happy!
There's a LOT more to effective cutting than just that. That explains the initial impact just fine, but the expressions needed to explain a blade moving through the target are significantly more complex.
We do make and use monomolecular tips in AFM (atomic force microscopy), though not for cutting. The sharpest blade in SciFi would be a force field or electron beam, that just slips between atoms and stops their attraction to each other. You could cut molecules into atoms with that.
I think I may have actually developed a tick from a combination of straining to see these marks and my finger raising in objection almost once per sentence.
This is something I've been pondering myself as I've recently gotten into micro bevels. I've been contemplating the various types of edge and blade grinds and asking myself, " why?".
We also need to remember that in combat, sharpness isn't the most important thing as you don't need to be severing limbs to pacify someone. Cuts a couple of centimeters deep in most parts of the body are enough to sever veins, arteries, tendons and render muscles inert. Not to mention that a long slice is gonna hurt like hell, and though relying on pain isn't wise in a fight, that combined with the injury itself and bloodloss will still help considerably.
Obsidian scalpels get to just a few atoms thick at the edge and has the potential to be 1 atom thick due to the crystalline structure of obsidian. You don't need a fantasy material to get an edge that thin. If you do careful cuts into flesh with them they are just as durable as stainless scalpels. The reason obsidian scalpels will stay sharp just as long as the stainless that's much thicker is because of the crystalline structure and how the edge breaks. The sides of the edge break off into microscopic chips exposing a new 1-3 atom thick edge just like flint knapping makes sharp edges. But they will chip back far enough up the blade to increase the thickness of the edge which is when they start to get dull. But that all depends on how careful you are when using them and why they are not daily drivers for all surgeons, use the same as a stainless scalpel and they will last half as long. So yeah you will need magic to make the blade last lol.
was a story about how some scientists looked at what was thought to be genuine damascus steel and they said they think they saw nano tubules and talked about some accounts of people saying original damascus steel may have been from iron asteroids, and may have unique properties from going threw the atmosphere. they said it would get sharper instead of duller. sounded like the nano tubules would break away and reveal fresh ones, kinda like shark teeth i guess. saw this around the same time i heard aboutt eh iron asteroid sword theory and its been confirmed in a few cases since, tutankhamens dagger.
Interestingly, divers hit the water with the palms of their hands to create cavitation, effectively decreasing the density of the water at the impact site
Great video. I like this explanation type video. I suggest using a sharpie pen instead of a pencil. It was a little hard to see your drawing on camera.
I recognized the issue with monoblades with my own scifi setting. I decided to get around the durability issue with engineering. You don't have to make the blade impossibly durable if it can repair itself between uses. Yes it will dull over the course of a single cobat encounter but eventually it will restore itself back to full sharpness
Great explanation skall. I'm a chef and my knife collecting tendencies have transferred to chef knifes. I tend to throw a micro bevel on my pocket knives. But much prefer a flat grind on my chef knives. Just to let you know how far my knife addiction has gone I have a 400$ edc pocket knife and a 900$ chef's knife but she rarely touches food shes too pretty.
From what I gathered, I would use a long reach sword with more durability for more defensive situations and a sharp thin sword for quick sneak attacks.
Another sci-fi additon to the mono mollecular blades is combining that with extremely high frequency vibrations. The theory is on top of that single mollecule simply sliding between the mollecules of the target, the vibrations push the mollecules asides. Theoretically possible in reality, It's just the same problem as the space elevator, no known possible material is strong enough.
Hey skall I have a sword I got from a fella that used it as a fire poker and im not honestly sure how to sharpen it or get rid of the bends the blade has additionally im not sure how to repair the scabbard as there is rust inside of it
I really like the freehand drawing stuff, but maybe next time you could use a marker or something darker so we can see what you’re talking about easier :)
A sad example of, "doesn't need to be sharp to cut," is industrial accidents with high-tension cable. The lack of following material adding resistance probably helps it cut deeply, if the cable hits with enough force to start the cut.
Odd question since I don't know much about medieval weapons and such: Lets say an "adventurer" in a medieval fantasy setting is able to teleport around during combat at will (a good example of such a character would be Ciri in The Witcher series), which weapons would be able to make the absolute most out of this?
There is a reason the Morakniv has been around for a long time. I'm sure it's not the best at everything, but it's really good at most things. I'ts just great when you have one knife, it's a multitool, basically.
Skal be like : "I heard you liked edges , so I'm being even more edgy than ever."
Let that bake your noodle
Edgier than Haachama's lore.
These puns
@@George_Bland my noodle is baked 🔥
The pencil was too sharp, I could not see the drawings
Nothing to add but this legit made me chortle.
"Let that bake your noodle" is a sentence I shall now incorporate into my vocabulary!
What will really bake your noodle is that phrase is said by The Oracle in the first Matrix movie.
Another thing you should add is saying "I have a brain noodle hurty" whenever you have a headache.
My noodles have, quite frankly, been thoroughly baked.
If I’m gonna be honest, they may have been a tad too baked. I need some weed too.
My liver has been fried
You poe boi.
You might want to use an ink-pen or a softer B-pencil - the light and reflections make the sketches hard to see at times.
or paradoxically, a blunter pencil
you guys could see the sketches?
A sharpie is clearly called for;)
Charcoal
like, at all times
I don't have time to actually watch the video just yet. Just popping in to say that is the greatest thumbnail I've seen in a long time. 😆
Same
nightmare fuel
That thumbnail, is a FREAKIN MASTERPIECE!!!
Way Better Art than Davinci's Mona Lisa!!!
I lol'd when I saw it.
But which turtle skullis the edgiest.
"Reptiles against the fathers of the Renaissance"?
Skall: *draws on page*
Me, who is watching in 240p: yes i can see very well
In one book there was monomolecular blade that was supposed to be sharpened by a power hungry force field which is eating away at the blade.
Thus if you blunt your blade enough to lose effectiveness you push a button, and field shave away some of the blade
I feel that most futuristic ultra-sharp swords would realistically go in this direction - instead of settling for a blade that cuts okay and stays sharp, just make incredible blades that dull or break in one or two cuts and find a very efficient way of either re-sharpening or replacing them mid-combat.
What about a solid energy blade edge instead of just matter?
@@WhatIsThatThingDoing Sure, but... the scientific meaning of "solid energy" is very vague. And will probably never be a thing.
Energy itself doesn't actually exist - it's just a theory that we use to describe how matter changes and where the... well, *energy*, comes from during these changes.
With that said, in the far, far future, let's assume that we learn how to out-right prevent all energy transactions on certain matter. With this tech-wizardry, we could then freeze the energy of a metal, essentially preventing it from changing, and use it to create a Solid-Energy Blade. It would not chip and it would not break, and these two abilities together would let you make the blade about as narrow as you'd like.
This is my interpretation of what this term would mean in real-life (psuedo)physics, and it's probably the best blade you could theoretically make while staying arguably true to what we know about the world.
With that said, the elephant in the room is if we will ever be able to screw around with energy itself on such a fundamental level... and I doubt it. And if we ever do... most weapon concepts we know of right now will probably be out of fashion.
@@WhatIsThatThingDoing really depends on the exact mechaincs of the device, for example in the book from which I described the blade the field was to powerhungry to feasibly provide it with enough juice for more than ~a minute of function while keeping it somewhat reasonably sized
“Drive home the point”
“Stay sharp.”
🤨
“Let that bake your noodle.”
Joke’s on you, Skal. I’m already thoroughly baked.
I like the drawn examples, helps get the point across further with an image to look at.
However the drawings are quite hard to see on a phone screen.
Might I suggest a fine liner? Or maybe a whiteboard?
These in-depth discussions are great, one of the more enjoyable vids in my opinion, great work!
Also that thumbnail is brilliant
Yeah i would have the same thing to say. It wasnt very detrimental but it was hard to see. Perhaps thats why numberphile uses brown paper
"Sharpness is the best thing since sliced bread" hah.
It's surprisingly logical, first they discovered sharpness, amazing!
Then they discovered they can use sharpness to slice bread, better!
But that would imply the sliced bread came before the sharpness...how did they slice the bread? Lolll
@@sephy980 it was done by hand, at first by slaves and then by dedicated craftsmen.
Did you mean butter? Ok sorry about this joke
Should have used a sharpie 😂😂
It’s not the worst thing to be fair but yeah would much prefer a whiteboard
The sound of a marker on paper kills me 😂
Or enhanced the drawing in post, current edit was basically light grey on shiny white, ideally, drawings on screen should approach a 100% black to white ratio out of the full dynamic range of the screen.
Holy hell your #2 pencil is washed out by your lighting.
This is probably one of the best Skal video in recent times, at least in terms of topic, explanation, writing and jokes.
"The sharpest edge is this!"
Holds up visably blank page
:woah, the sharpest edge is no edge, he's speaking in koans:
Turns page, drawing faintly appearant
😑
Jokes aside, maybe use power point slides, I get why you went with this approach, but I couldn't see the demonstration 3/4 of the time. Non the less, love your work
It's not bad on a properly balanced screen, but a lot of gamers increase their gamma so they can see things in deep dark dungeons and other dank places, and loose thier upper color gamut. Could also be hard to see on a cellphone for resolution reasons
@@nosajimiki5885 1080p tv, balanced by my lady for watching hockey, but thank you for letting me know it's visible on some screens, i was curious as he seems to check the screen several times
@@Liminallunatic TVs are usually set up to maximize contrast more than computer screens because it makes otherwise drab video look more stunning. This usually results in loosing out on both the upper and lower most ranges of your brightness gamut. Since Skallagrim is doing video editing, he probably goes in on a semi-regular basis to reballence his monitors, otherwise his hue balance can shift over time making his videos look fine on his screen, but blue, green, or pink on other people's screens... the issue is that this usually means that content creators work in ideal environments allowing them to see those very upper and lower contrasts that get lost on other devices.
The sharpest edge is the piece of paper itself!
@@omnitroph1501 maybe, the real sharpest edge, is the friends we made along the way!
Me: "Should I watch the Skallagrim video first this morning, or one of the others in my sub list?"
Skal: *Makes a TMNT2 reference in the thumbnail*
Me: "Cowabunga it is"
I was SURE that once he started talking about the "razor"-thin blade, he was going to segue into this episode's sponsor to peddle razors.
Or dollar shave club.
Or Harry's.
best part of these videos is your comprehensive understanding of mathematics and and practical physics. its refreshing.
This was very informative!! Thanks for breaking down more of the mechanics of how "sharpness" works on a bunch of different levels
Big fan of the longer videos ,Skall. Keep em coming!
So, my knife is not too dull - I'm just too weak. Got that now, thanks!
This is better than any of the knife videos on blade geometry. Thanks!!
My absolute favourite representation of this concept are scanning electron microscope images of the tips of clinical grade needles, they are nearly *perfect* when brand new, and after a single injection the tip is visibly squished, the hole it leaves after the injection is barely bigger than the needle itself and, obviously, it pierces with next to no resistance at all
The thumbnail that humanity doesn't deserve.
Well done. Best edge explanation video I have seen so far out there.
Great video and title. I hate when I hear men tell younger guys or women they wouldn't understand. This is very educational and you know very well what you are talking about. Thanks for this video sent it to alot of friends to show them.
Scandi is the most useful to me.
Big props for the thumbnail dude
On topic of edge roll: In CNC metal working one very important thing is how thick of a shaving the tool produces. The reason for it is that the material itself keeps the cutting edge of the tool from rolling or otherwise deforming. It is weird how you can use a lower-quality cutting tool and completely destroy the edge by trying to go easy on it, yet get great results while pushing it harder. If not enough material is removed, the cutting edge either bends or breaks outward, in the direction that the shaving is coming off at. With deeper cut there is enough material on either side of the edge to prevent this. Not only that, but thicker shavings carry off a LOT of heat that's produced during cutting so the part and the tool stay cooler, which also helps with longevity. This is very similar to why it's so easy to dull a drill bit with a hand drill. Go a bit too quick on the RPM without enough down pressure and the bit will dull in seconds. Put the same bit in a drill press that turns slower and produces about four times the down pressure and the bit will last for a long time.
This doesn't really apply to swords and such, but still is IMO a nifty tid-bit that goes somewhat against what you'd expect.
Looks interesting, but the paper’s too bright and I can’t see anything on it
Fun fact regarding convex edges--they are actually essentially the same as a V-style edge of equal edge angle, but with the shoulder removed. Contrary to what many think, the intersection of two arcs does have an angle to it, and while it's possible to have a convex edge that's thicker than a V-grind, it's because it's a thicker angle at the apex! However, the shoulder of the convex with an equal edge angle to the V-grind will go further back on the blade. When drawing comparisons very often people make the mistake of holding the shoulder depth as fixed, which makes convex the thickest possible geometry to "connect the dots" but that's not how it works in real life when applying an edge to a tool, and so the real advantage of a convex is that it allows you to thin the geometry behind the edge without sacrificing edge stability at the apex, and so it will be a little more penetrating than a V-grind of equal edge angle.
I really apreciate than kind of content. Really good video Skall.
Things like the edge being aligned straight, high coefficient of friction/some amount of micro-jaggedness (being too smooth may cause it to slide and roll the edge in, making it blunter. Cutting involves dragging and tearing...)
having thin enough a contact cross section to raise applied pressure,
being hard enough but not too hard it’s brittle,
being enough resistant to elastic deformation,
having a favorable weight distribution, blade geometry/edge tappering and blade wideness.
Best obsession about sharpness I've read is in Terry Pratchett's "Reaper Man".
Also the most kinestetic way of describing a voice ;)
Just realized: This pandemic has now lasted long enough that I have your length hair and I imagine roughly your amount of swords (apparently pandemics awaken the collector in me).
I was considering buy a fat belly blade like your green handle one. Damn! That head cut is way more better than I thought.
A sword seller I met at a ren faire tried to use a misinterpretation of this to justify why the entirely blunt sword I was looking at was actually sharpened...lmao
I found a book called The Razor Edge Book of Sharpening by John Juranitch a helpful expansion on a lot of this discussion. They even did "clinical trials" with different steel. I think it was a poltry processing facility where people are using knives all day every day as a job. Great video thanks!
so part of my bg is in the world of cnc machining. it was explained to me that the radius of the carbides we used basically concentrated the pressure down to such a small area that the heat generated formed a plasma which is what did the actual cutting. id think that a mega damage entity would be capable of generating such forces on nearly anything with a bit of a taper to it. hell when i got my logsplitter it had a rounded edge but after the first few pieces the pressure had honed that into a near razor edge.
''I had a lot of pun here''
Got the idea but were not able to see very much the drawings , good explanations and examples , keep the good work =)
Sharpness is the greatest thing since...sliced bread? I actually chortled. well done, sir.
Something I haven't seen mentioned anywhere so far is the concept of self-sharpening blades.
It would be very similar to rat teeth in nature: There are two layers, stacked next to each other in two sheats. One is softer than the other, gets abraded more quickly, and so the edge gets thinner, only the hard layer remains at the top, and can then be worn down in turn.
wasn't going to watch the video, but that thumbnail got me. good job!
Good amount of information there, even if you're not actually have anything to do with real swords. As a craftsman (wood and metalworking) i really appreciate all the info.
You nailed the thumbnail this time skall
I liked this video as soon as I heard the first pun. It was pretty sharp and I could tell you would get to the point.
I read somewhere that the only material that produces a radius that is as close to 0 as possible is obsidian, specifically the edges of an obsidian flake. Obsidian is probably the only thing hard enough to sustain that edge, but it really cannot do much, as it's quite brittle because of the hardness.... On the subject of sharpness, when I was an apprentice carpenter the master carpenter spent an afternoon teaching me honing and sharpening skills. I managed to get a chisel sharp enough that it actually managed to get stuck in concrete... But only once, as when I removed it, the tip was pretty much ruined. Like you say, getting things sharp isn't the issue, having a material that's strong enough so it can stay that sharp despite wear and tear is.
Thank you for this video!
Usually when I sharpen a sword myself it's sharp enough to cut paper and does well against bamboo... But very often against two liter Coke bottles doesn't do well.
I choose to put a more durable Edge because for years my primary test cutting target has been bamboo in the Bamboo Grove near my house.
Bamboo supposed to be similar to bone and from the pork I have cut on I agree that fresh bamboo is very much like cutting bone that is fresh.
But Coke bottles take a much finer Edge to cut well then bamboo or meat.
My edges that will cut bamboo and meat well also can be whacked on thin frying pans without taking any Edge rolling or chipping.
But again they're no good for cutting on two liter bottles which is a good backyard fun thing to do.
My edges would be able to hit against shield and armor well, but surprisingly not many modern targets
Very good video skall, realy bring quality content
The next video in my notification list includes a hydraulic press. There you can see sharpening a blade is not needed to make it cut if you have a bit more force behind it. 100 tons are sufficient for most cutting needs.
Good video. I was wondering if you might follow up with something about differential hardening and the impact on edge retention. The type of steel and how it is hardened at the leading edge matters a lot. I found that if you use something like O1 tool steel you can heat the cutting edge with like a map torch to cherry red (whole thing needs some heating) and quench it then file to a pretty formidable edge, then the hardening gradient gives you strength away from the lead edge.
I made a 90cm single edge blade with 8mm thick back edge 40mm blade width and a convex bevel. It was ludicrously sharp but was able to cut wood and leather easily.
I tried this with similar dimension 1095 and it completely went to hell, blade cracked.
Love the videos, understanding blade cross sections are a kind of an obsession for me at the moment.
New point of reference for explaining "sharp" edges on swords. Thanks!
1:54am Can't sleep, let Skall teach me the way of the blade
Can someone tell me what is this sort of curved kindjal / gladius that Skal is holding in his right hand at 20:45 ? Or post a link?
A good way of imagining how something really sharp will break is Obsidian, which is the sharpest thing we know. It can cut hard, but it won't survive the first strike, and that if it is a dagger, any bigger and it breaks under its own weight.
Good information. Thanks for the presentation!
Skall, or anyone who is able to help, I have a question. Why does a slice cuts but if I press the blade straight against a surface it is less effective?
I don't understand why is this so, if someone could explain I would be very happy!
P = F/A
Pressure = Force/Area
youre welcome
There's a LOT more to effective cutting than just that.
That explains the initial impact just fine, but the expressions needed to explain a blade moving through the target are significantly more complex.
We do make and use monomolecular tips in AFM (atomic force microscopy), though not for cutting. The sharpest blade in SciFi would be a force field or electron beam, that just slips between atoms and stops their attraction to each other. You could cut molecules into atoms with that.
Im sorry hoss but glare and other factors make seeing pencil on that paper near impossible
Even though I could barely see the drawings at times, what I've seen was a great representation :D
I think I may have actually developed a tick from a combination of straining to see these marks and my finger raising in objection almost once per sentence.
An unusually comprehensive and scientific discussion.
This is something I've been pondering myself as I've recently gotten into micro bevels. I've been contemplating the various types of edge and blade grinds and asking myself, " why?".
Kyber Knife and other T-spine blades have the most interesting edges to me. So thin.
T spined swords are super neat
Aren't Khyber knives named for the strategically important Khyber Pass?
@@johndododoe1411 yes, Matt Easton talked about that a lot on his channel
We also need to remember that in combat, sharpness isn't the most important thing as you don't need to be severing limbs to pacify someone. Cuts a couple of centimeters deep in most parts of the body are enough to sever veins, arteries, tendons and render muscles inert. Not to mention that a long slice is gonna hurt like hell, and though relying on pain isn't wise in a fight, that combined with the injury itself and bloodloss will still help considerably.
90 degree edges can cut pretty deep. I work with particle board, and have gotten a few stitches from the edges.
It would be nice to listen about different types of layers of steel that forming the blade's anatomy
Obsidian scalpels get to just a few atoms thick at the edge and has the potential to be 1 atom thick due to the crystalline structure of obsidian. You don't need a fantasy material to get an edge that thin. If you do careful cuts into flesh with them they are just as durable as stainless scalpels. The reason obsidian scalpels will stay sharp just as long as the stainless that's much thicker is because of the crystalline structure and how the edge breaks. The sides of the edge break off into microscopic chips exposing a new 1-3 atom thick edge just like flint knapping makes sharp edges. But they will chip back far enough up the blade to increase the thickness of the edge which is when they start to get dull. But that all depends on how careful you are when using them and why they are not daily drivers for all surgeons, use the same as a stainless scalpel and they will last half as long. So yeah you will need magic to make the blade last lol.
was a story about how some scientists looked at what was thought to be genuine damascus steel and they said they think they saw nano tubules and talked about some accounts of people saying original damascus steel may have been from iron asteroids, and may have unique properties from going threw the atmosphere. they said it would get sharper instead of duller.
sounded like the nano tubules would break away and reveal fresh ones, kinda like shark teeth i guess.
saw this around the same time i heard aboutt eh iron asteroid sword theory and its been confirmed in a few cases since, tutankhamens dagger.
Interestingly, divers hit the water with the palms of their hands to create cavitation, effectively decreasing the density of the water at the impact site
That's why you start out with an iron bar, make the edge damn near monomolecular, and turn it into cuendillar.
Great video. I like this explanation type video. I suggest using a sharpie pen instead of a pencil. It was a little hard to see your drawing on camera.
Looking forward to the Single Edge Qama review
Great informative and clear video
I recognized the issue with monoblades with my own scifi setting. I decided to get around the durability issue with engineering. You don't have to make the blade impossibly durable if it can repair itself between uses. Yes it will dull over the course of a single cobat encounter but eventually it will restore itself back to full sharpness
Great explanation skall. I'm a chef and my knife collecting tendencies have transferred to chef knifes. I tend to throw a micro bevel on my pocket knives. But much prefer a flat grind on my chef knives. Just to let you know how far my knife addiction has gone I have a 400$ edc pocket knife and a 900$ chef's knife but she rarely touches food shes too pretty.
From what I gathered, I would use a long reach sword with more durability for more defensive situations and a sharp thin sword for quick sneak attacks.
what about a concave primary with a convex secondary?
That devil edge single edge qama is a beast of a cutter. Lol. I own one and although she is way overweight and painful to cut with, she does cut nice.
Is this the episode where we discover his skillfull freehand drawing?
Another sci-fi additon to the mono mollecular blades is combining that with extremely high frequency vibrations.
The theory is on top of that single mollecule simply sliding between the mollecules of the target, the vibrations push the mollecules asides.
Theoretically possible in reality, It's just the same problem as the space elevator, no known possible material is strong enough.
Worth adding, if such impossibly strong material was found to make weapons from, the same material would logically be used to make armor.
It would be intetesting to test Conyers Falchion or a quality replica cutting tatami.
the best thumbnail i’ve seen
Hey skall I have a sword I got from a fella that used it as a fire poker and im not honestly sure how to sharpen it or get rid of the bends the blade has additionally im not sure how to repair the scabbard as there is rust inside of it
And rust all over the blade but I got rid of most of it
Does anyone know how they sharpen the blades at Angel Blades? Supposedly the sharpest swords around
best thumbnail evaaaar! :D
I really like the freehand drawing stuff, but maybe next time you could use a marker or something darker so we can see what you’re talking about easier :)
I demand you invest in a flipchart and a bowtie for these occasions.
Best thumbnail ever!
A sad example of, "doesn't need to be sharp to cut," is industrial accidents with high-tension cable.
The lack of following material adding resistance probably helps it cut deeply, if the cable hits with enough force to start the cut.
Very educational. Thank you!
Great job! Definitely feel like my edge has been sharpened! :)
Odd question since I don't know much about medieval weapons and such:
Lets say an "adventurer" in a medieval fantasy setting is able to teleport around during combat at will (a good example of such a character would be Ciri in The Witcher series), which weapons would be able to make the absolute most out of this?
Ah yes, the riddle of steel. We won't let Thusla Doom trick us with his trap of the flesh, or ability to thrall those within his cult.
how well do different swords work against onions, carrots or tomatoes though?
Is the monodo from xenoblade chronicles a practical weapon
There is a reason the Morakniv has been around for a long time. I'm sure it's not the best at everything, but it's really good at most things. I'ts just great when you have one knife, it's a multitool, basically.
That single-edged blade from 19:15 to 21:15 (ish) next to the gladius is frikkin' beautiful. What is it?