I just had first lesson in Aikido with Jo and was surprised to see that some of the staffs were octagonal and some were round.

Can someone explain what is the difference and if there are any advantages to round or octagonal shape of the Jo?

  • Could it be weight? Sep 12, 2012 at 8:56
  • We teach to think of a bo or jo as no different than a sword or a chain; you learn to lock with each, to tie with each, and, most relevant to your question, cut with each. Other claims I've heard are that it improves grip and durability; I've not looked into these claims much.
    – stslavik
    Sep 12, 2012 at 15:41

11 Answers 11


My suggestion, based purely on experience as a wood worker, would be that octagonal staffs would traditionally have been easier to make.

The machines we have available these days can bang out nice round dowel pretty easy, but once upon a time, these things would have been make by hand using tools like planes and draw knives. Using tools like that, an octagonal shape would take half the amount of time to make.

Perhaps other traditions have grown up around the use of the different shaped staffs, but in my opinion, that would be a separate issue.

  • Interesting. I would think that a staff would have been traditionally round seeing that sticks and trees naturally grow in that shape. It would seem easier to smooth out the roundness of the staff rather unless the octagonal shape had a different purpose or meaning within a style.
    – user15
    Sep 14, 2012 at 0:23
  • 1
    @Matt-Chan, that would be true if you are using a stick that is the right size, but typically you would be shaping things out of a board from a larger tree. This gives you much more control over the grain in the final weapon. The straighter the grain, the better.
    – nedlud
    Sep 14, 2012 at 1:21
  • Traditional staffs from kungfu were bamboo. I'm guessing it's no different in Japan than in China. It seems quite alot more difficult to make bamboo into any other shape than round
    – Raf
    Aug 28, 2017 at 20:58

Fascinating question; I'd like to know the answer. I found one potential answer:"The octagonal cut of all the staffs also gives you nice surface contours for locks and submissions."

Several sources (none of which are reliable enough to quote) imply that octagonal weapons are associated with Okinawan martial arts, but that seems to be in the context of the nunchuku.

I spoke with one of my favorite jo authorities (whom I didn't obtain permission to quote/name) who relayed that one of his colleagues has an octagonal jo. Apparently,

One of my friends who does SMRJ has one. Supposedly it's "Gonnosuke style" It will cut you!! He emphasis striking with the edge of the jo's tip, like using the corner of a very small table that is moving very fast...

I've found another author who suggests that the octagonal edges can cut

The hakaku-bo, however, was octagonal, and its angular edges made it viciously effective when unleashed against an unprotected target, since they cut along with the strike. Dave Lowry also a nice, readable, survey of jo training

This provides another potential alternative answer, although it involves some inference. Apparently the "Pilgrim's staff" or Kongojo is octagonal, and there may be a separate formal school of training for combat with the kongojo.

*update: Caveat: the following is personal opinion Looking back over all the answers, I'm unconvinced by the "more wood" and even of the "Gonnosuke" answers. With respect to the "Gonnosuke appellation, although I don't deny that vendors may sell octagonal jo as "Gonnosuke style", I'm skeptical that the octagonal jo is connected to the founder of Shindo Muso Ryu Jodo in any linear fashion. (Although I studied SMRJ for a very short time, my SMRJ teacher required round weapons, and I didn't find any mention of octagonal jo's in any of the SMRJ websites I visited. I would expect that if anything were "Gonosuke style", it would be SMJR).

As far as the "more wood" goes, the only way that I can imagine that making a difference is in placing more mass on target; as others have noted, I'm not sure how much "more mass" would be involved. Furthermore if the goal is to increase the mass*velocity equation, I personally would choose a denser wood rather than an octagonal shape.

I think the most credible answer I've seen is "personal preference".

However I'm eager to see any support for any of these hypothesis, or even new hypothesis.

  • @MatBanik Obviously that depends on what you consider the "radius" or "diameter" of an octagon. Normally the "radius" of a regular polyhedron is measured from its center to any of its vertices (circumradius), implying an octagonal weapon would have less wood than a round one. Sep 12, 2012 at 23:38
  • I'd say the edge would cut you no matter what shape the bo is. The edge will be sharp on either version.
    – oekstrem
    Sep 25, 2012 at 13:39

Octagonal weapons are less prone to torque out of your grip; same reason bolt heads aren't round–the flat edges give the weapon a means to find purchase, against the bones and skin of the hand. Whether it's enough of an advantage to prevent disarming, different issue. The disarms we practice in my FMA classes aren't turn-the-stick-on-its-axis disarms. Every little bit helps.

I hear claims they'll do more damage because you can "hit them with the pointy part", but I don't see how that would be possible in a combat situation. Even if it was possible to align a strike in that fashion, I'm skeptical the difference would be worth any effort.

  • Lacrosse Sticks, which definitely do experience similar amounts of torque, have a squashed hexagonal cross section for this reason; the corners and non-round shape help you keep your orientation. You can see ovular cross sections on sword grips from many cultures as well. Once again, that is to help keep orientation, and in the case of swords, keep good edge alignment.
    – PipperChip
    Dec 15, 2015 at 18:24
  • @PipperChip Good point about orientation, although we're talking about octagons here. Dec 15, 2015 at 18:30
  • 1
    I suppose my point is that circular objects don't have flat surfaces for you to grip; other surfaces (with edges) allow you to do so. Those examples are cases where this principle has been applied. In any case, you have a good answer.
    – PipperChip
    Dec 15, 2015 at 23:20

When I visited Japan (specifically the area around Fuji) I noticed that there were walking sticks for sale which were a bit longer than an Aikido Jo, and usually octagonal:

octagonal staff Full sized image and source.

I do believe that - as a walking staff for a pilgrim - octagonal would present several practical advantages, including: easier to manufacture, better grip, less prone to roll away from you if dropped - especially on a steep trail.

From the linked article I now find out it is also traditional to stamp it when you reach specific waypoints (a practice that could also work for people visiting temples, I suppose?)

I wonder if this could be the original source from which the Jo was derived, despite being shorter (you can also try googling "八角杖" for more images).

One more thing: if this is indeed the origin for the idea of an octagonal section staff... please understand that they may have adopted the octagon (instead of an hexagon, for example) for some numerological/symbolic/doctrinal/ritualistic reason.


From my experience the octagonal weapon inflicts more pain especially when incorporating the staff in joint/finger locks and throws as the edges will hurt your bone structure more than a nice round staff.

I'd say it would likely do more damage as well, as @davenewton mentioned, because of the pointy bits - but I have not seen actual evidence of this.


If my walking staff is smooth round and shiney,then my hand is sliding up and down all over the place, the more sides to the staff the better the grasp or hold I have to steady myself as I walk.

I find the octagonal staff the best walking aid that allows my hand to stay firmly in one place on the staff or easily adjust up or down.


Actually, I'd say the very first poster was dead on, despite the temptation to look for some "martial artsy" kind of answer. Round staffs were made from tree branches that happened to be the right size. Octagonal staffs were easier to make from lumber in an age where shaping a round pole would have been quite time consuming. Some staves were actually square. The advantages of sharper edges to strike with and give better grip were merely incidental to this.

  • 1
    Welcome to the site. You should take the tour to see how we work. your answer would be much improved if you provided some references for your claims. Aug 29, 2017 at 8:23

Simply, smaller surface area concentrates force.

This becomes more important when your foes wear armor, as you want small surface area hits to break the bones in vital combat areas, like wrists, and feet, both which can not be armored well if mobility has to be retained, but where a hardened piece of rawhide would simply glance the blows from a round weapon because it doesn't "bite" in like an edge does.

Octagonal shape also lets you use the staff better as a mobility aid, because it doesn't roll around when using it as a bridge/ladder.

  1. Hakkaku bō/jō have the advantage that they deliver more damage. The edges severely raise the probability of breaking bones.

The round bō/jō have the advantage that they deliver less damage. The roundness lowers the probability of breaking bones.

So at the end you just should ask yourself what your views and those of your style are. In aikidō I would think a hakkaku bō would not really fit. In martial arts focussed on battlefield combat on the other hand, the hakkaku would be a better choice.

  1. Round weapons weren't as easy to make as polygonal ones.

  2. Hakkakubō/jō offer better grip.

  • 1
    Can you add any objective evidence to support your answer?
    – Mike P
    Sep 5, 2016 at 11:47

Hold up your hand as if you are clenching around a 25mm (1") to 20mm (1 1/4") stick/bo, look onto your thumb knuckle! (down the 'virtual' axis of the stick/bo!)

What do you see?

I see at least six, near straight bones! (plus a gap!)

My thourghts are 'ergonoics' (confort/grip!) + maximum stiffness (maximum distance = "1 sun" ~30mm for point to point on the hexagon or octagon!)

  • 1
    I'm not following how this relates to octagonal versus cylindrical. Are you saying the sides should match knuckle lengths? May 20, 2020 at 14:27


So that when you drop it, it doesn't "run" away from you ^_^

*Edit: Oook, don't really know what I said that offended so many of you, but I felt that it was a fairly solid guess (at least as legitimate as assuming that that extremely minute edge gave any sort of notable increase in a staff's striking power).

Let me take a crack at being a touch more clear. When you are fighting someone, being disarmed of you weapon is a pretty bad thing. Some would even call that the end of the fight. That said, being able to reacquire your weapon should the worst happen is a fairly high priority I would say. Now, when something round drops to the ground, it has a depressingly high chance of rolling away from its point of impact meaning that not only have you been disarmed and your chances of winning the fight have plummeted dramatically, but now your staff is ALSO rolling away from you, further decreasing the chances and likelihood of you ever reacquiring the thing that is supposed to be keeping you alive. On the other hand, a nice octagon shaped staff is FAR less likely to roll once it's dropped. Even if you accidentally kick it or step on it, it's tendency for rolling is dramatically lessened, meaning you won't end up making matters worse for yourself in your fumbling attempts to rearm yourself and stepping on it isn't likely to cause you to slip around like some comical cartoon henchman (such a quality is only detrimental to you since trying to get your opponent to slip on your downed staff is not a reliable enough tactic to justify using it in combat).

Please note that I'm perfectly alright with being proven wrong and would love to hear how that is the case. I am NOT a martial artist, but I DO consider myself fairly well equipped in the common sense department. There are many other perfectly valid answers on here, my personal favorite being that the octagon shape is easier to keep a grip on and apply leverage to during grappling and such (which, in my understanding, is a massive part of historical martial arts weapons training). Also, the fact that the octagon shape would have been easier to craft back in those days seems perfectly reasonable as well, though I hesitate to assume something like that when the same age of people were able to create such ingenious methods for crafting swords and armors. If they wanted a round stick, I have no doubt they'd have made themselves a round stick. I just threw in my two cents because I hadn't seen anyone else mention it earlier and it seems to me to be one of the most likely reasons why a wooden shaft with no axe head or something on any of its ends might greatly benefit from NOT being uniformly round throughout it's entire length.

Anyway, if I'm wrong I welcome a response explaining to me why, as I clearly have a great deal of interest in the subject, but just silently down-voting my comment is in no way helpful. Perhaps my friendly manner came across as mocking or mean spirited. I apologize if that is what you all thought, but I assure you that that was never the intent.

Have a good day all. Cheers!

  • Not rolling was covered in an answer from three years ago martialarts.stackexchange.com/a/5819/5926 - if this was the main reason - why would they do Octagonal as opposed to Triangular? (which would roll even less). Drawing on references or personal experience are vital in writing a good answer.
    – Collett89
    May 16, 2018 at 7:09
  • While you are correct in the fact that "not rolling" had been mentioned before, the answer that you linked did not mention it for the same reasons that I did and seemed to over complicate that useful function with the scenario of trying to use the staff as a mobility aid (as a "bridge" or "ladder"). That is very situational, hence why I felt the need to simplify the great benefit of your staff staying put if dropped. A triangle or even a hexagon would likely feel like garbage and really hurt the hands to use in combat. Common sense is a more than passable stand in for writing a good answer.
    – Badger
    May 16, 2018 at 18:24

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