Japanese garden machete (nata) : an example of the benefits of the chisel grind

[@jordanwilliams9151]

Well explained, short and sweet. Thank you for teaching people the chisel grind!

[@bluebeastgamer3005]

Excellent explanation of the knife grind!!! Can you or anyone please tell me how can I get one of the Japanese garden nata hatchet??? Any links or websites would be appreciated!!! Thanks so much, Barry

[@CliffStamp]

@mccullenj On a similar note, all broad axes (the ones which are used to square logs) are either chisel, or very close to chisel ground on the back side. They are essentially used like large planes and have to be able to cut flat to logs to square them off. Of course no one does that locally anymore, it is all milled.

[@V3ND10L4]

Great explanation! I learned a lot! 😊👍🏾

[@mccullenj]

Very good explanation. I find that most modern chisel grind knives are made for left handed use. I believe I saw a video were Wako explained how Japenese lumber workers use the chisel ground hand axe to trim limbs off flush from the main trunk.

[@CliffStamp]

The original specification video had a full description of the bevel, it has a hollow relief grind on the back and the front has a flat grind to a wide convex bevel. The simplest solution is to sharpen on benchstones, it isn't as difficult as you might seem but you could start out just using a rod to microbevel the front and then just burr removal the back.

[@SpartanJohns]

Way to go on making a point! Pun intended. :)) But seriously: great demo! It's something really logic, but few people think about it. Honestly I would have never thought about it! Great video!

[@CliffStamp]

@docnightfall The problem is that the asymmetry of the chisel grind means that side loading is very significant and thus it is much weaker than a v-grind of the same cross section. Normally the side loading is just the unbalanced forces, on a chisel grind the side loading is essentially proportional to the force used in the cutting. This means chisel grinds are loaded laterally an order of magnitude greater.

[@CliffStamp]

@knivesandstuff I remember, way back when people were spending thread after thread wondering why Emerson was using chisel grinds on the opposite side. There were long discussion about wound channels, strong vs week side cuts, trapping/deflection on the flats, etc. . Then finally someone notes, "oh yeah, that - well the first ones made didn't picture well so he reversed the grind.".

[@leaddispenser9]

What brand is this? Thank you for the info. I see its place

[@CliffStamp]

@mccullenj That is really nice attention to detail to use a similar profile for limbing, you are taking very precise care there. I have a few friends who actually work in that field, but they all use fine saws, it is rare to see larger blades here. But yeah, it is optimal for that just like Wako has noted.

[@docnightfall]

@CliffStamp I was thinking about it just now and it seems that an asymmetrical edge's tendency to "turn" when it meets heavy resistance is just the edge passively being deflected closer towards the path of least total resistance, which intuitively would be path where the side loads are most evenly distributed. So "relaxing a little"-- using the weight of the knife, letting it impact with a supple wrist-- would probably be good for durability.

[@CatacombCustoms]

Fascinating comparisons, do all Nata's have this type of grind or must I search for a specific name for it?

[@8steve88]

That's one of the very few benefits of a chisel grind, still wouldn't convince me, I don't use my knives for woodcrafting very often. It's weird but I like my knives symmetrical, liner-locks mostly, or fixed blade. I also take the pocket clips off but that's more for comfort although most pocket clips look like they've been slung on as an afterthought. Very interesting video, thank you.

[@haywoodf]

Good pithy & contrasting demo. Thanks

[@CliffStamp]

@knivesandstuff Yeah, there is a reason why chisel, plans, broad axes, etc. all have the grinds that they do. The handle on this though is abrasive to the point it is almost unusable though without rounding out that center cut out, the wood is left raw from the saw cut and as it is oak it is not soft and forms a very hard edge. Again, not a big deal to sand out in any case.

[@CliffStamp]

@docnightfall As a quick estimate then, the edge would need to be three times as thick (given a specific force/skill) which would mean personally I could not take it much less than 0.075" - which rather ironically is exactly the current thickness of the secondary convex bevel.

[@haywoodf]

@knivesandstuff Granted. Unfortunately on some forum posts the disconnect is worse than from poor english skills. Some posters don't even spend the effort to read enough or any context and then parrot hearsay barely related. This is a great example of concisely passing information in an interesting way. You both do it well. Any included linguistic challenge is not a problem for me. lol :-)

[@ajaxtelamonian5134]

I have a billhook with that chisel type grind the exact one is an English Hertfordshire pattern which is a bit meatier.

[@docnightfall]

@CliffStamp I'd love to see how it does with a wider bevel and a longer radius on the convexity. The mild steel face grinds so easily, it's just begging to be optimized.

[@CliffStamp]

All nata's have a similar shape, however the blade grind can vary significantly, a common v-flat for example can easily be found.

[@CliffStamp]

I have not handled them, they look nice, traditional and clean designs. They use a number of steels, mostly traditional cold work steels with high purity and very fine carbide and aus-grain (sk8), very nice knife steels.

[@CliffStamp]

@knivesandstuff Yeah, it was kind of amusing to see how all the threads, which were at one point a very hot topic suddenly just fall off and everyone sort of hung their head and pretend they were not involved and had not spent post after post trying to explain the tactical nature only to find out it was because some guy behind a camera liked the knife turned the other way.

[@CliffStamp]

@docnightfall I can prevent that from happening by radically changing the bevel and ensure that it will fail first at the edge itself, i.e., in the last 1/16" or so by applying a heavy relief grind there. This will lower the failure point, but cause premature failure to happen in the very edge and not see nothing - nothing - nothing and then the entire convex bevel will deform/dent.

[@docnightfall]

@CliffStamp I agree, the point of using a tool in the first place is to make life easier, and so in the tool should be made to serve the user and not the other way round.

[@CliffStamp]

@docnightfall If you relax during the impact and let the knife move in the cut, the load can only be lateral -if- the medium is strong enough to constrain the knife (really hard woods can still do this) otherwise it will just move instead of being bent by the lateral load. The problem with this is that the knife, in these cases, can come right out of the wood.

[@Prometheus1111]

do you still have this machete? you should throw it in your chopper videos that you've been doing. how do you feel about durability on this being that it is only partial tang construction?

[@CliffStamp]

Yes, however the handle later failed and the blade itself suffered a severe crack. I don't have any issue with partial tangs, all my customs are made that way even the very large blades.

[@Prometheus1111]

sad to hear that. looked pretty nice. i was tossing around the idea of getting a traditional styled japanese knife. i somehow missed this video. it always pleases me when that happens.

[@docnightfall]

@CliffStamp I see. I suppose you could still thin it out behind the edge, raise the bevel line.

[@CliffStamp]

For chopping tools on stiff vegetation you want to finish with the highest polish which is practical in terms of time and effort and start with a grit which is low enough to remove any damage. I find that in general 1000/4000 or similar works well, but if you have visible damage you may need to back way down to 100 grit at the start.

[@CliffStamp]

@docnightfall Yes, that is it exactly. The edge load is unbalanced even on a straight vertical cut due to the asymmetry in the grind. It will thus tend to rotate. If the wood by its nature produces an asymmetric load (knot, grain, split, etc.) -and- you force the blade to stay true in the cut, the edge will suddenly have a huge lateral strain and all knives are extremely weak laterally compared to compressive resistance - which is basically infinite in comparison (1000:1).

[@CliffStamp]

@docnightfall I could also not act so much like a gorilla when I chop wood and focus more on cut placement than power. The problem is that I don't want to refine the edge to such an extent that if I am using it in the winter, with gloves, in a hurry and do a sloppy and heavy cut that the edge takes a significant turn.

[@CliffStamp]

@docnightfall There is that. I do intend to run this again the weekend and relax a little and see what happens, if it is ok I may lay the primary grind back. The problem is though that if this goes it is going to go completely due to the nature of the grind and the way it will be loaded. The entire convex bevel is very likely to deform if over stressed.

[@glytch5]

where did you get that thing?

[@CliffStamp]

There are many stores which sell them on line. Just look for ones that stock Japanese tools.

[@mikeparkermikeparker]

Very informative, thanks!

[@docnightfall]

@CliffStamp You could fill the gap with epoxy before sanding it.

[@CliffStamp]

@docnightfall But, I use WAY too much force. There is no need to use half the effort I am doing if your intention is just to cut the wood in two pieces. But again I enjoy it, I am evaluating the knife for emergency situations, I want to know what will happen if I do chop heavy, etc. (plus it looks way cooler on video).

[@fredzamith]

interesting video man.thanks

[@CliffStamp]

@docnightfall Yes, it isn't difficult to fix.I am just letting it stay like it is for now anyway as I am curious to will it wear down in use. Winter is coming now anyway and I have at most a month before I have to wear gloves and at that point all that does is add traction. It does however give snow/ice/water a place to hide.

[@CliffStamp]

@docnightfall The goal is to provide just enough counter resistance to keep the blade from doing that (and endangering yourself) and not so much that it can not move at all and thus you would maximize the strain on the edge (but also maximize the chopping power). If you look at my hands during the chopping, I do not have a very tight grip laterally at all for this reason and the blade can rotate significantly.

[@knivesandstuff]

@mccullenj haha.. you are right about wakos video and limbing.. Its a running joke I have when people say why is a chisel grind good.. and i say "when you want to use it like a chisel" so tactical chisel knives are awesome when you want to clean scalp someone :) All those "left handed" chisel grinds are so they can take the correct orientation photograph for marketing.. lol.. nothing more. crazy right? you need to use a chisel grind the right way or it will bend too easy.

[@florincochintu8691]

You could do same thing with both if you hit on right angle. I do like japanese one to be honest.

[@51sr86]

私も長年使っていますが、 片刃の鉈は木材を切るのに最適です。 現在は ｵﾝﾀﾘｵﾅｲﾌの18ｲﾝﾁを使っていますが。

[@eqlzr2]

The real moral of this vid is, use the right tool for the job. Period.

[@CliffStamp]

@Warescrackdown It would be difficult to jig shapen due to the multi-faced bevel, in order to keep it as the original profile you have to flat sharpen two bevels and then convex another one. It is not difficult if you are used to hand sharpening, and the steel itself is very simple to sharpen as it grinds easily and has minimal burr formation. But no problem, I will put up a sharpening video later.

[@docnightfall]

@CliffStamp Although, if by saying "relax a little", what you actually mean is "activate gorilla mode", then yes, that would probably induce greater stresses on the edge. :)

[@John..18]

Rest in peace, my friend,

[@rallen568]

Are you from Newfoundland ?

[@paulie4x1]

Say Heah Cliff, I need your help, What's the difference between a Silky Nada single edge and the double edge and for bush crafting which one would you suggest, Thanx You in advance. ,, .

[@CliffStamp]

Unless you have a specific need for a chisel (single grind), get the double. The chisel grind are specialty tools.

[@paulie4x1]

Kewl BeanZ, Cliff, Thanx You, I really appreciate hearing advice from you, Thanx You. ,, .

[@paulie4x1]

Say Heah Cliff, I'm not bragging, But I have some of my knives posted on Google Plus, Your welcome to look, and tell me what you think, OK. ,, .

[@CliffStamp]

Send me a link.

[@paulie4x1]

Just search Paulie 4X on your search on Google Plus. ,, .

[@CliffStamp]

It is from Japan Woodworker.

[@47ArmyGuy]

Great info

[@Fluxxcapacitor52]

It's called a "Nata"... Silky makes a decent one for the money

[@johnmutton799]

Works the same as a hewing axe!

[@btrswt35]

What if your left handed?

[@CliffStamp]

They grind them the other side as well.

[@btrswt35]

Cool

[@billwatson3527]

Try using that grind left-handed. Oh! I guess that is what you would call a right-handed knife.

[@knivesandstuff]

@haywoodf This is why I like youtube. You say something on a forum and get bounced on five different ways from people that dont understand what you are saying because of the decline in english. a video speaks a thousand words and provides evidence at the same time.

[@zachtanner3461]

I would totally use a Chisel gring if I wasn't left handed

[@CliffStamp]

Yes.

[@dakotam5165]

I WAS BROUGHT HERE BY HIGURASHI.

[@sebenzalover]

rip

[@knivesandstuff]

@CliffStamp everything except the last in fighting is a load of crap.. :) a normal chisel would optimally have you slash across your body left to right for a right handed person. the left side chisel optimally wants you to expose your body and slash right to left.. No matter what.. in a fight you are not going to choose your cut to match the grind. There is not a single remote reason on earth for a chisel grind to be better for fighting otherwise history would be full of them.

[@micktheweld]

Oh... I see now. Lol I'm going too keep my mouth shut from here on.

[@knivesandstuff]

See.. The irony here is that you've just demonstrated using a chisel as a chisel.. lol..

[@forestrussell-yount1355]

fret video

[@monkwild7448]

Your accent is confusing me

[@CliffStamp]

It confuses me too.