Sciencey Thoats About Tangs


Teh almighty YuTub algorithm has recommended this video to me:

Why military gear isn’t always a good idea…

And whilst I do agree with the title and the overall message of the video, I do have some objections to it. It is not an issue that can be distilled down to a universally true video quip.

First the agreements:

Military gear that is issued to grunts en masse needs to be essentially consumable. The grunts will lose it, steal it and/or destroy it with gross abuse and negligence on a regular basis. I read about conscripts in the Austrian army in WWI breaking their bayonets by opening cans. Stealing was a problem even in former Czechoslovakia, with the UTON  even though that was not issued to every grunt but mainly to paratroopers. The knives disappeared regularly as the soldiers reported them “lost during exercise” even though they had to subsequently pay for them and everyone knew they took them home. Those knives are good, but they are not as excellent as some people think they are “military grade” is definitively not always a synonym for “high quality”.

Now the disagreements:

A good bushcraft knife needs not to have a full tang to be reliable. It is more complicated than that – rattail tangs were and are used in even swords and machetes to this very day and they are not useless. Puuko is a survival knife with hundreds of years long tradition for example. The above-mentioned UTON also has rattail tang, and one that does not go all the way through the handle at that, and still it is a knife that can withstand serious abuse. I have put some of my knives with similarly thin tangs through their paces, both full-length and half-length hidden tang and they withstood serious abuse just OK (although I was only using them as knives, see further). Hidden tang alone is not an issue, the overall construction and heat treatment are.

My biggest beef is with the presented “knife gets stuck and you try to wiggle it out”. Sorry, but if your knife gets stuck in something hard right up to the hilt, then you are probably an idiot for using the knife wrong. A knife is not, and should not be used as a pry bar. But let us say one were to use a knife for making firewood splinters from a log by batoning. That is a legitimate use for a bushcraft knife and it can get stuck that way. It happened to me with my working knife and I had to use serious force to get it out. However, if you try to “wiggle it out” by holding it solidly against the ground and pushing at the handle sideways, you are definitively an idiot for trying to remove it in the least effective and most dangerous way imaginable. Simply put, abuse like that shown in the video does not represent even remotely reasonable and appropriate use of a knife, not even a bushcraft knife that should be sturdy.

Another thing I would like to address is the handle material. It is shown to be natural leather rings and apparently, not overly compressed and not glued together or hardened. That is a problem because it is a soft material that can easily be compressed and give way for the tang to bend. A wooden handle – like on European medieval swords and daggers – significantly improves the resistance of the tang against bending. If the rings were glued together and hardened by hot wax or boiling or epoxy, it would improve the durability and resistance of the handle significantly too.

The thickness of the tang and the blade at the weakest point plays a far greater role than the width. The force needed to bend/break a flat profile rises linearly with width but exponentially with thickness. If you double the width of the tang, you double the force to bend/break it. But if you double the thickness of the tang, the force needed to bend/break it can rise approx ten times (I do not know exactly how much, the calculations are complicated and I cannot pretend to understand them). So a knife with a thickness of 3 mm and full width (~15 mm) tang will be about as strong as a knife with a thickness of 4 mm and 6 mm wide hidden tang.

A role also plays the heat treatment of the tang. A fully hardened tang will be stronger and more resistant to bending and will spring back when bent. But when bent beyond the plastic deformation, it will be more prone to permanent damage and/or catastrophic failure when straightened again as shown in the video. Unhardened tang – that is used throughout history for swords from Europe across Asia all the way to Japan I might add – is easier to bend but can subsequently be straightened again.

And lastly – anything will break if used wrongly or excessively abused. A knife is not bad because it cannot be used as a pry bar and a pry bar is not bad because you cannot cut cutlets with it. When I made the custom machete, I tested it by hitting a brick with it – but I still advised the customer not to do that.

Comments

  1. lochaber says

    I used to be a big fan of military surplus store stuff when I was younger. That love of military gear pretty much died with my enlistment…

    When I was younger, I thought military gear was generally well-made, and stuff in military surplus stores was generally pretty cheap. Probably still not bad fro someone looking for some starter camping gear, as long as they aren’t concerned about weight… Hell, I still have an old (Swiss?) rucksack I bought nearly thirty years ago, and have dragged over a couple continents, and used to carry back home various junk, rocks, groceries, scrap metal, and all kinds of stuff. It does need some repairs and mending, but it’s served me well, and at this point, has some sentimental value.

    I’m also wondering if the ~90s were pretty much the best years of military surplus stuff? I suspect a lot of nations were disposing of excess inventory after decades of cold-war stockpiling and build-up? The couple times more recently when I’ve ventured into a military surplus store, it was less actual issue gear, and a lot of knock-off, imitation, and mall-ninja shit, and mostly over-priced at that.

    Then again, maybe the market itself has changed, especially here in the U.S., with all these various nazi sub-groups and what not, who put on more tactical gear to go to walmart, than the actual military infantry did on D-Day.

    I broke so much damned gear while I was enlisted… I think I destroyed at least three e-tools (that hinge is a major weak point…), and the issue compasses suck (I always used my old orienteering/geology silva when no one was looking…)

    As to knives, maybe it’s just me, but I feel that “full tang” is a definition that has slightly changed over the years? I feel like it used to just mean that the extended through the length of the handle, so rat-tail and similar designs would qualify? I may be wrong on this, but I just remember things like “half-tang” or “partial tang”, where the metal attached to the blade only extended part way into the handle, so that in some uses, a lot of force was being applied to the lower bits of the handle, without transmitting that force directly to the tang/metal/blade, so it acted like a lever, and was more likely to break the handle off of the knife.

    For larger knives, and hard-use/abuse-prone knives, I think it’s very important that they be full-tang, but for smaller, and properly used knives, it’s probably not as important. But, I also tend to use it as a red-flag for shortcuts in construction and such, as it’s easy for me to see that it’s full tang on a slab-handled knife.

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