Talk:Fuller (groove)

"Blood Groove"

I did a full text book search using blood groove as a search term and found many references from the 19th and 20th century describing how the groove was used for blood letting, bleeding, drawing blood, etc. On the contrary I found no older reference to fuller in these texts. Many 19th century medical books describe in detail how to use the groove for blood letting. An old farmers almanac described the same thing, and mentioned that without it, a live hog's muscles may contract so a twisting motion will be needed to remove a knife with no groove, due to suction and muscle contraction. An old text from England explained a blood letting practice of Vikings on victims, using the groove. I find that most information discrediting the "blood groove" all come from one of two sources, and when the original articles are tracked down, those authors use no citation for their statements. I would tend to say that hundreds of years of noted medical and martial practice, all describing the blood groove as a blood letting aid, are on to something. The lack of any merit to a blood groove as a bleeding purpose is too new and unfounded for me to discredit what has been maintained and said for hundreds of years. -- JohnnyGillette. 2:04, 12 October 2009 (UTC)

I have no idea if this is correct or not, but I thought the "blood groove" term referred to the fact, that if one is cleaning the blade with a cloth or chamois, you can guide the wiping motion by pressing the wiping implement partially into the groove, thus ensuring that neither the wiping implement or the fingers holding it during the wiping motion stray to the business side of the blade. -- Cimon Avaro; on a pogostick. 11:03, 14 September 2006 (UTC)

The "blood groove" story really seems to be folklore and it isn't accepted any more by people who understand blade geometry. As it stands, the intro paragraph contains the following two sentences

A fuller is often used to lighten the blade, much in the way that an I-beam shape allows a given amount of strength to be achieved with less material. Longer knives or bayonets intended as offensive weapons may employ fullers (also incorrectly known as 'blood grooves' or 'blood letters') to lighten the blade while maintaining its strength. They allow the blood to run down the blade upon cutting into flesh.

The last sentence contradicts the one preceding it, so I'm going to delete it and insert language to the effect that this was a popular belief. —Mrrhum (talk) 20:52, 10 May 2013 (UTC)

Rejection of the term blood groove seems to stem from the dubious explanations given regarding suction and drawing of blood. The validity of these explanations is irrelevant to colloquial naming

In nearly every other culture where steel blades have been fullered with a channel, that channel will be called "blood groove/channel/gutter/etc". Use of this term is common around the world for hundreds of years CharlesedwardbishopIII (talk) 16:06, 10 June 2021 (UTC)

"Strengthen"

The phrase "their purpose is to lighten and strengthen" is not correct. The purpose of a fuller is to lighten a blade. It is clear from the physics discussion in the article that a fuller cannot strengthen a blade. Any opposition to removing "and strengthen?" Mathandubh 10:47, 14 May 2007 (UTC)

Fullering does not lighten the work material (whether or not it is a blade) as no material is removed, but rather spread CharlesedwardbishopIII (talk) 15:54, 10 June 2021 (UTC)

Little balance to article

Why is there a long section on Japanese swords and not on, e.g., modern weapons, Ulfberchts, or pretty much every sword since 500 AD? I get samurai are cool, but the lack of balance to this article doesn't make sense. There also weapons made outside of Japan with multiple fullers and other things that seem more relevant to an article on fullers. Maybe the section on the length of Japanese fullers should remain in the Japanese swordsmithing section. If there are no objections, I suggest removing the section and simply adding a list of sword-making regions (with links) as a replacement section. Throwawaygull (talk) 00:10, 13 August 2013 (UTC)

"Stengthen" = Flexing strength

The purpose of fullers in long blades, beyond saving money in steel and making the blade lighter and more balanced,, is to give them some ability to flex when under pressure and when being twisted, much like a railroad rail or I-beam used in construction. A three-sided musket bayonet could thoretically be driven against a hard surface, and only be bent, not shattered. It is easier to bend a piece of iron or steel back into shape, rather than to try to recast the shattered remains thereof.

95thfoot, Saturday, June 09, 2007, 9:10 PM EST

With all due respect, the edits made to suggest that a fuller adds strength are unsupported by engineering fact. Even the AG Russell reference first declares that the purpose of a fuller is to lighten the blade. The talk about it strengthing a blade is misleading because they J Hrisoulas is comparing different geometries. A fuller is all about getting the best strength while reducing weight. Note the statement "When combined with proper distal tapers, proper heat treating and tempering, a fullered blade will, without a doubt, be anywhere from 20% to 35% lighter than a non-fullered blade without any sacrifice of strength or blade integrity." The fuller does not increase strength, it makes the blade lighter without significantly decreasing strength. How could removing material increase strength??

Look at the Beam_(structure) article. The i-beam takes the same amount of mass, and makes it stiffer than the same square beam. Or, since mass near the center doesn't help the stiffness much, one could take the square beam, carve out fullers, and end up with a lighter beam with about the same stiffness. In any case, the i-beam structure is designed to resist vertical deflection (in that picture.) Saying a fuller makes a knife or sword stiffer means it is stiffer in the cutting direction. Has anyone ever used or seen a knife or sword where the stiffness in the cutting direction was less than the stiffness in the sideways direction? The main reason to use i-beams in construction or railroads is exactly one of cost. One uses less steel, ie less cost, and achieves the engineering goal of managing the loads in use. The references to "strengthening a blade" should be removed. (BTW, "strengthening" is vague. What types of bending does the fuller help prevent?)--Mathandubh (talk) 11:35, 6 March 2008 (UTC)

One final comment. Look at the article on Second_moment_of_area. Section 7.5 calculates the moment of inertia for an i-beam. It is clear that the resulting value will always be less than for the square beam of the same outside dimensions. This means the i-beam will bend more than the square bar for a given load. Thus the i-beam is less stiff. Fullers cannot stiffen a blade! But they can lighten the blade, without affecting the stiffness much in the cutting direction. I will remove reference to strengthening the blade here.--Mathandubh (talk) 15:41, 6 March 2008 (UTC)

Both are technically valid. Strength and flexibility are linked. Think of willows bending instead of oaks breaking. Fullers do not stiffen blades, but stiff blades aren't necessarily a good thing. Stiff blades and snap or shatter. "Strength" can have many meanings, most based around "strong." "Strong" can mean the ability to resist weight, in which case a fuller is not strengthening. "Strong" can also mean effective, then in many cases, a fuller does make a blade stronger.

To make a blade more ridged, a riser (pretty much the exact opposite of a fuller) is used.

That is semantics, though, and for the sake of clarity I see why it was removed. Throwawaygull (talk) 01:15, 13 August 2013 (UTC)

Physics section

I just thought I'd mention that the physics section of this article is completely wrong. When I have more time, I'll gather up some sources and fix it. In the meantime, I'll just mention that the forming of the fullers has nothing to do with leverage or tensile strength. The fullers are formed through plastic deformation of the metal caused by hertz-contact stress. When steel is heated to red or yellow-hot, surface tension is not a factor, but the metal becomes very plastic (formable), similar to playdough (not nearly as soft, of course). Imagine pushing a finger into a block of playdough; the surface will depress and take the shape of the finger, and the displaced material will move sideways, forcing the adjacent material to rise from the surface. The shape of the fuller (tool) determines the shape of the fuller (groove).

The displaced material can increase the strength (resistance to bending) of the blade by increasing the thickness of its cross section in various places. However, it only decreases the weight of the blade if the displaced material is subsequently removed by grinding or filing it away, returning the blade to its original thickness. However, this is typically not done because it would lower its rigidity. Instead, this allowed the smith to create a blade using less steel, therefore being of lower weight and cost, but with the same size and rigidity of a heavier sword. Zaereth (talk) 21:33, 25 January 2014 (UTC)

This is not a good article title

"Fuller (weapon)" suggests that a fuller is a weapon, whereas it's really a tool used in making weapons. 109.157.79.50 (talk) 15:39, 4 January 2015 (UTC)

Perhaps. This article is about the term as used in blades; that includes both the tool used in bladesmithing and the groove left in the blade. Maybe Fuller (blade) would be better? You can go to Wikipedia:Request for move, and see if there is any objection to such a move (title change).Zaereth (talk) 12:02, 5 January 2015 (UTC)

A better title would be "fuller (groove)". The 2015 objection above is correct that "fuller (weapon)" suggests that a fuller is a weapon, whereas it's really either the tool to make the groove — fuller (metalworking) — or the groove itself, fuller (groove). Per WP:BOLD, I am moving it, rather than begging anyone for permission to move it. Quercus solaris (talk) 23:44, 14 February 2021 (UTC)

Japanese terminology

The article listed various types of "bi" as different types of groove on Japanese swords (bo-bi, futasuji-bi etc.), whereas it should be "hi" (bo-hi, futasuji-hi, etc.). I have no idea what possessed someone to write them as "bi". I corrected the spelling. Tsuka (talk) 07:32, 20 March 2016 (UTC)

Either spelling in English is acceptable, and common in reliable sources. Like Peking to Beijing, English spellings do not always match Japanese pronunciations. (I know, that's a Chinese city.) According to Kokan Nagayama in the book, The Connoisseur's Book of Japanese Swords, "...please note that "hi" is usually pronounced "bi" when preceded by other characters." Zaereth (talk) 20:24, 20 March 2016 (UTC)

Why is there even a section for reference to Japanese work? This article is about the English term fuller CharlesedwardbishopIII (talk) 15:57, 10 June 2021 (UTC)

suction

nothing is said about this... when you stab someone or something with a blade, there is a great deal of suction, having a gutter run up the length helps release the pressure, which means the weapon doesn't stick inside whatever you stab. It makes it easier to pull out the blade. Yes a the fuller also serves a structural purpose, but this is the more practical reason why one would want a groove running up the length of the blade... depending on the blade, it may be very easy to penetrate, but then very difficult, more difficult in fact, to pull it back out. You can use a potato and a kitchen knife to see what I'm talking about for yourself. Lostubes (talk) 02:57, 26 June 2017 (UTC)

That's an urban myth. (see discussion @ Talk:Japanese swordsmithing.) A living body is under pressure, so there is no vacuum. Blood and bodily fluids are actually trying to push the blade back out. Even with a dead body, this doesn't hold true. Flesh itself is very strong and difficult to penetrate. This can easily be tested on a dead pig, or better yet, a dead bear. (Both are very close to humans in skin texture and toughness, which is why med students practice on pigs, although a bear is much closer to humans in anatomy.) Once again, you'll find that the body does a poor job of generating any vacuum. There is no structure to hold a vacuum from collapsing in on itself, so what you basically have is a bag of fluid, fluid which follows the blade right out, filling any vacuum. (A potato is different because it has a solid shape and doesn't pull inward to make up for any displacement. The potato instead holds a large amount of friction around the sides of the blade. Because of static friction, it is easier to push the blade in because it is already moving, but more difficult to start the blade moving as you pull it out.) Even if a vacuum were to develop, it could be no more than 15 psi at best. If you multiply the area of the blade which is in direct opposition to the vacuum by 15 psi, (not the sides, but only the edge of the tip, you have at best -.015 pounds of suction, which is so minimal as to be non-existent.

What really should be avoided in any combat blade is a saw edge, which will be most likely to snag on the tough flesh. This should not be confused with a serrated or scalloped edge, which actually increases cutting ability and prevents snagging. Zaereth (talk) 07:41, 26 June 2017 (UTC)

I might add that, for swords in particular, what is really needed in combat is lowered weight and good balance. (Either that, or vastly increased strength.) Lower weight equals faster movement, which is critical in real combat. Unlike the movies, a real swordfight between people who are trying to kill each other lasts an average of one to three seconds. Ten seconds would be an extremely long fight. (It's quiet, fast and brutal.) The three stages of a fight are tip-to-tip, which is where most of the fighting is done. The faster a person can get their blade into position, before the opponent can do the same, the better their chances for survival. The second stage is blade-to-blade. At this point, the outcome is already decided. Last of course is blade-to-body. (In contrast to a choreographed Renaissance fair or motion picture, the primary goal in a real swordfight is not to hit the other guy's sword, but to try as best as possible to bypass the first two stages and go directly to the third.) The primary purpose of a fuller (in a sword at least) is to lessen the weight while maintaining structural integrity. Zaereth (talk) 22:08, 26 June 2017 (UTC)

Fixed the "I-beam" muddle.

I fixed the "I-beam" muddle. See the edit summaries for some explanation. The I-beam is clearly referring to the caps of the "I" being at the extremes of long cross-section direction, which needs no more stiffness. The Physics section gave a nice, and fairly accurate, explanation of the compressive and tensile stresses in a beam (even though it was fully uncited). It seemed to me that the direction where more stiffness is needed would be the short cross-section direction. It wasn't jiving. Then I reviewed the talk page and saw in the "Stengthen" = Flexing strength section that others were also concerned. So, basically it's a mistake to go on about I-beams unless it's more clear about which direction, and it's supported with reliable (not similarly muddled) sources, and it's applicability is clear and supported. Usualzukor (talk) 19:10, 7 June 2018 (UTC)

Lightening

Is there a source for the 25-30% lighter claim in the introduction? The entire introduction is not annotated but some of the information is repeated further down. This specific claim is not and it seems to need justification, given that the main purpose the article ascribes to fullers is increasing bending moment to weight.

Based on most swords I've personally examined this does not seem like an average figure. Most fullers I've seen are quite narrow and do not meaningfully change the sectional area of the blade.

The lede typically doesn't need sources, because everything should be sourced further down. The lede is supposed to be a summery of the rest of the article. I'd have to look to see if any of the sources further down give that actual number, but to me it seems about right for swords. Keep in mind we're talking volumetric weight, not area. A typical katana with a fuller will usually weigh about 2 to 2 1/2 pounds. Without a fuller (my preferred style) typically 3 to 3 1/2 pounds. That's a 30% reduction in the fullered sword. Those same weights are typical of Merovingian swords, Viking swords, etc., both fullered and not.

In combat any little bit helped. (See my comments two sections directly above this one.) It also helped in ancient times because steel was a very, very expensive and rare commodity, so anything you could save for the next sword, and not have to file away, was very important. Zaereth (talk) 01:23, 1 August 2019 (UTC)

Fullering doesn't reduce weight, just as stamping with other types of shaping dies do not reduce weight

Grinding and filing reduce weight, but grinding and filing are not fullering

It would be more appropriate to say that a fullered blade may be lighter weight than a similarly sized blade that has not been fullered CharlesedwardbishopIII (talk) 16:00, 10 June 2021 (UTC)

Rewrite

This entire article needs to be rewritten

One of the sources used for the article is Alex bealer "the art of blacksmithing" who never once in his book refers to blood grooves as "fullers". On the contrary, he defines fullers as tools used to make blood grooves (among other things)

Blood grooves have never historically been called "fullers" and despite assurances of self proclaimed experts like Matt Easton no evidence is ever provided

IMO this article should contain a proper definition of fuller in the context of blacksmithing with reference to it's use in bladesmithing but NOT defining the groove itself as a "fuller", because it isn't. CharlesedwardbishopIII (talk) 16:15, 10 June 2021 (UTC)

I beam comparison not accurate

As a structural engineer, the groove technically would decrease the strength and increase the flexibility of the shape. A block of steel is more rigid than grooved steel, or any material for that matter. If cost was no issue, we wouldn't use I beams in structures. We'd make big hunks of square shaped steel.

From an engineering perspective, I'm fairly certain the groove is largely done to decrease weight. It would NOT strengthen the shape. 97.119.239.12 (talk) 01:19, 17 April 2023 (UTC)

See my comments in the above sections. Part of the trouble here is separating all the myth from the reality. For example, the myth that fullers are supposed to reduce suction when pulling a blade from a body (also, see my comments above). Someone made that up one day because it sounded good in the head in the same way that TV writers make up "science" for CSI and Star Trek. If it sounds even the slightest bit plausible, then people believe it and spread it around, and that's what we have to contend with here.

That happens a lot with swordsmithing and blacksmithing in general. People often don't realize that for most of history these things were kept very secret. They were as top-secret then as missile technology is today. Maybe even more so, seeing as they didn't even have patents for most of history. Therefore, it was all a big mystery to most of the population, and still is today. Even words like "tempering" and "hardening" are still confused to this day, although the difference has always been known by blacksmiths.

As someone who both forges swords and uses them, I have read a lot on the subject and have a ton of firsthand experience. When it comes to the I-beam explanation that all depends on how you look at it, and that often leads to confusion which is where these myths arise from. (For example, the myth that, scientifically, bees should not be able to fly. Now, if a bee were the size of an airplane that would be true, but that myth comes from a novice misunderstanding of Reynolds number.)

The first thing to understand about swords is that the lighter you can make them; the better chance you have to win a fight. People often think the opposite, but that comes from watching too many Conan movies and renaissance fairs. In a real fight, every bit of weight you can remove increases your speed a little bit, and it's all about speed. "Speed is life." A real swordfight is fast! On average, 1 to 3 seconds is all you get, and most often it's near the lower end of that range. The three stages of a fight are tip to tip (this is where nearly all of the fighting is done), blade to blade (at this point the outcome is already decided), and blade to body. The goal is to try as quickly as possible to bypass the first two stages and go directly to the third. In this lightning-fast arena, any bit of weight you can shave off will greatly increase your chances of survival.

When it comes to the I-beam analogy, you can look at it both ways. If you cut away a groove it can make a heavier sword significantly lighter without much loss in strength. If the groove is forged, then it can vastly increase the strength of a thinner sword without an increase in weight.

If you make a sword too thin it will be incredibly light and fast, but it will just bend or break in combat. Increasing the thickness does increase the strength, but also increases the weight and therefore slows reaction time. However, you can also use geometry to increase the strength without such an increase in weight, and an I-beam does just that. True that the strength doesn't match that of a solid piece of square-bar, but it's actually fairly close. You lose a lot of weight for a rather minor reduction in strength. Now, if we made buildings out of solid bars rather than I-beams, the size of those buildings would be drastically reduced because all the added weight would quickly surpass the structural integrity, and they would risk being crushed under their own weight. The increase in strength is quickly canceled out by the weight. So the analogy is a sound one, but too many laypeople out there still cling to the mythology and the misinformation. Zaereth (talk) 19:51, 17 April 2023 (UTC)