Kiridashi knives are marking knives, carving knives, leather knives, and everyday carry (EDC) knives. In fact, they’re probably the closest we can get to the best EDC knife. They’re cheap, easy to use, and extremely durable. They’re loved by carpenters as marking knives, they’re used by leather workers for detailed cuts and paring, they’re handy for cutting ropes and opening boxes, and they’re used for pruning and detailing bonsai trees. The purpose of this article is to introduce you to the kiridashi knife, and show you why you need one in your tool kit.
What Are Kiridashi? | Design and Properties | Traditional Uses | Contemporary Uses | How to Choose and Care for a Kiridashi
What Are Kiridashi?
Kiridashi are simple and versatile single-bevel knives from Japan. They’re often called kiridashi kogatana in Japanese, which translates to “small knife for cutting out”, which is spot on. Just like their name, their design is also very minimalistic. They’re a single plate of carbon steel which has been ground diagonally on one end, to create a narrow, fine cutting edge. They can be inserted into bamboo scabbards or wrapped with cord to fashion a grip, but they’re often just used as-is, as a single piece of steel.
In the past, kiridashi were one of the most commonly used tools in Japan. Children would keep them in their school pencil cases, to sharpen their pencils and use in art class. Adults would always have one at the ready for when a box needed opening, or a string needed cutting.
These days, in Japan, they’re most used by carpenters as marking and carving knives, by kimono makers for shearing fabric, and by bonsai horticulturists for pruning. But the potential of these handy multi-functional tools is endless.
Design and Properties
Kiridashi are long, straight pieces of steel with a diagonal grind culminating in a sharp point. They come in a few different sizes, which are differentiated by the width of the blade. For example, we sell this Kakuri kiridashi in 18mm, 21mm and 24mm. Most kiridashi are 15mm, 18mm, 21mm or 24mm but you can find them in 9mm, 12mm, 27mm and 30mm too. The length and thickness of a kiridashi varies depending on the manufacturer and the style – but they’re typically 180mm to 200mm long and 2mm to 4mm thick.
The Steel
Most Japanese kiridashi are made from either Yasugi Shirogami or Yasugi Aogami carbon steels. Kiridashi made outside of Japan are usually forged from vintage files, so they’ll most often be made from 1095 or W1 carbon steels.
There are a few key qualities that you want to look for in a knife’s steel: sharpness, edge retention, and corrosion resistance. So let’s look at these qualities in detail regarding the four common kiridashi steels.
Sharpness is a difficult thing to quantify when talking about steel. In general, steels with higher carbon content can become much sharper than steels with lower carbon content. But sharpness depends a lot more on the quality of the grind and sharpening process than on the material used. A low-carbon steel ground by an expert knife maker will be sharper than a high-carbon steel ground by a beginner. So when we look at the steels, all we can measure is the potential sharpness based on the carbon content.
Carbon content (average):
- Shirogami: 1.15%
- Aogami: 1.15%
- W1: 1%
- 1095: 0.96%
So, the two Japanese steels have more carbon, which means they have more potential for sharpness. If kiridashi knives made from all four steels were ground and sharpened by the same person, the Shirogami and Aogami knives would be sharper than the W1 and 1095 knives.
Once your knife is sharp, you need it to stay sharp. So edge retention is a very important quality to consider. You can tell how well your knife is going to retain its edge by learning how hard the steel is. Harder steels retain their edges longer than softer steels, so softer steels require more frequent sharpening. Let’s take a look at the hardness of our four steels on the Rockwell hardness scale.
Hardness:
- Shirogami: 62.5
- Aogami: 62.5
- W1: 50.5
- 1095: 13
Again, the Japanese steels come out on top, with W1 slightly trailing, and 1095 left in the dust. So if you get a kiridashi made from 1095 steel, you should expect to be sharpening it a lot more frequently than you would if you had gotten a Shirogami or Aogami knife.
Finally, let’s talk about the bane of all knives: rust. All carbon steels are susceptible to corrosion. If you’ve decided to buy a carbon steel knife over a stainless steel knife, you’ve already accepted that you have to take certain steps to avoid rust in exchange for having a very sharp knife that holds its edge well.
Some carbon steels, however, are slightly less susceptible to rust than others. Steelmakers add chromium to make their steel corrosion resistant. The higher the percentage of chromium, the higher the corrosion resistance. Most carbon steel has no chromium added, but some steelmakers add a little to give it some protection against rust. So let’s take a look at the chromium percentages of our four:
Chromium content (average):
- Aogami: 0.35%
- W1: 0.15%
- Shirogami: 0%
- 1095: 0%
While not close to the 10.5% of chromium required to make “stainless steel”, the small amount of chromium in the Aogami and W1 steels will make a difference when it comes to corrosion, so that’s an important point to consider.
In conclusion, Shirogami and Aogami steels have the potential to be much sharper than W1 and 1095 steels. Shirogami and Aogami hold their edge for longer than W1 and 1095 steels. And Aogami is the most corrosion-resistant steel of the bunch, with W1 coming in at second place, and Shirogami and 1095 tied for last.
Shirogami and Aogami are clear standouts as the better steels for your kiridashi, with Aogami edging into the top spot because of its corrosion resistance. One other important thing to consider, however, is that chromium helps Aogami resist rust, but it also makes it more difficult to sharpen. So if you want a knife that’s easier to sharpen, you’d be better off with Shirogami.
The Grind
The angle of a blade’s grind is important for determining both how strong it will be, and how sharp it will be. A knife ground at a lower angle will be sharper and less strong than a knife ground at a higher angle. Kitchen knives need to be very sharp, but not so strong, as they typically cut softer materials like meat and vegetables. Most kitchen knives are ground somewhere between 15-20 degrees. Kiridashi should still be sharp, but they need to cut harder materials, like wood, leather, and sometimes even metal. So they’re ground between 20-30 degrees – about the same as a chisel.
The grind angle generally isn’t listed in a knife’s product description or packaging. But if it’s something you’re able to measure or find out when purchasing a kiridashi, it’s important to consider. If you’re going to be using your kiridashi for crafts, cutting paper stencils, leatherwork etc, it’s better to opt for a sharper blade with a lower grind angle, around 20 degrees or lower if possible. If you know you’ll be using it for woodwork, metalwork, bonsai pruning etc, you should try to find one with a higher grind angle, around 30 degrees or more.
Traditional Uses
Kiridashi were traditionally used as carving knives in Buddhist temples, where the monks would carve wooden statues for worship. They spread across Japan to become multi-purpose utility knives. People used them to carve spoons and small toys for children. They used them to cut cloth and rope. And, even quite recently, children were required to bring them to school to sharpen their pencils, and to cut paper and fabric in art class.
Aside from the general day-to-day uses, many fields had specific ways of using kiridashi, to the point that they became essential tools in many areas such as woodworking, gardening, and more. Let’s take a brief look at some of them.
Woodworking
It’s hard to find a good marking knife for woodworking. You’ll find one that’s great for delicate marking, the fine and intricate stuff, marking out patterns for carving, or dovetail joints – but it’ll be useless for making deep cuts. You’ll find a great big marking knife that can really get in deep and do the job, but good luck trying to be delicate with it. And most of them don’t last. They’re either disposable, with flimsy replaceable blades, or they’re so over-machined that if they chip, break or dull, it’s easier to just buy a new one than to maintain the one you have.
That’s why kiridashi are so great. Their fine points and slim profiles allow them to be neat and delicate; you can mark out intricate patterns, small dovetails and other joinery. Their exceptionally sharp Japanese carbon steel blades allow them to cut deep without much effort. And their simple, user-friendly, straightforward design makes them almost indestructible, easy to sharpen (even though you’ll rarely need to), and easy to maintain.
Not only can they mark out the intricate stuff, in a lot of cases, they can do the intricate stuff too. After you use your kiridashi to mark out your chip carving design, you might find that you end up using the kiridashi to carve the piece instead of digging through your toolbox to find a chip carving knife. After you mark and cut out your dovetail joint, if it’s not a perfect fit, instead of finding a chisel to deepen the shoulder of the joint, it’s easy enough just to shave down the excess wood with your kiridashi. These are things you’d never dream of doing with a typical marking knife – but kiridashi aren’t typical marking knives.
They’re marking knives, they’re carving knives, they’re whittling knives, heck, they can even be chisels too if you want them to be. They’re extremely versatile, one of the best bladed woodworking tools around.
Sewing
Kiridashi are extremely useful tools for seamstresses and dressmakers. Even traditional kimono makers use kiridashi daily in their work to score and shear fabric, and to cut threads and seams.
Because kiridashi are thin, low-profile, and single-bevel, they allow for extremely precise cutting. So dressmakers and kimono makers can rely on them to make detailed cuts for their intricate patterns and designs. Their simplicity and sharpness makes them an easy tool to just pick up and start using without much preparation or thought, so one of the most common ways they’re used in the textile industry is to quickly and cleanly cut away any excess fabric after sewing a seam.
Kiridashi help kimono makers to create stunning and intricate designs with precision and accuracy. They allow tailors, dressmakers and seamstresses to shear fabric to the required size, cut threads and seams, and remove excess fabric with a few quick movements.
If you’re looking to downsize your sewing kit, put away your thread cutters, utility knives and fabric shears, and replace them all with a single kiridashi. Alongside sewing needles, thread, and pins – a kiridashi could quickly become one of the most essential tools in your sewing arsenal.
Bonsai
Bonsai growing and shaping requires meticulous attention to detail, so using a very sharp and narrow blade is crucial, as it allows you to reach tight spaces and make cuts that would be more difficult with a larger knife or scissors.
Since kiridashi are single-bevel knives, they’re ideal for making intricate and detailed cuts. That’s why they’re a must-have tool in the delicate art of bonsai. A single-bevel blade’s cutting edge can press directly against what it’s cutting. So if you were to prune a branch off of a bonsai tree using a kiridashi, you could cut it flush with the trunk of the tree, leaving no part of the branch behind.
A common way bonsai horticulturists use kiridashi is to create jin, shari and uro. These all refer to different forms of deadwood that exist conjoined with the living bonsai tree. To create a jin, a bonsai grower uses a kiridashi to strip the bark off of one of the tree’s branches, which kills the branch. The branch will stop growing and fade to a whitish color while the rest of the tree thrives around it.
To create a shari, you would do the same process as with a jin, but on the trunk of the tree rather than a branch. This creates a multi-colored and multi-textured trunk with a very aged look. Both jin and shari are mimicking things that happen to trees in nature when they’re exposed to harsh environments. The picture at the top of this section shows a bonsai with a large shari and multiple jin, which strike a sharp contrast against the dark coloring of the living trunk and branches.
Finally, creating an uro requires you to cut out part of the trunk with your kiridashi, creating a hollow opening. This also happens to full-sized trees in nature. When a branch dies and rots away, it will often leave a hollow where it once was.
Kiridashi are essential tools for bonsai enthusiasts, as they allow you to prune and shape your delicate trees with ease, as well as mimic nature in the practice of creating jin, shari and uro.
Contemporary Uses:
EDC Knife/Utility Knife
Kiridashi make great everyday carry knives. Although, because kiridashi are fixed, exposed blade knives, you’re going to need something to cover the blade to make it safe to put in your pocket. Kiridashi makers often sell simple bamboo scabbards and sheaths to put them in, or you can craft a small sheath out of thick cloth or leather. Because of their low profile, they don’t take up a lot of space. You can keep one in your pocket, your backpack, or your glove compartment. They really are the best EDC knife.
Their pointed tips and very sharp edges make them useful for cutting ropes, opening blister packages, opening letters and boxes, and almost any other cutting task you’d need them for. They can do anything a retractable utility knife can do, only better, as their blades are sharper, and last far longer.
Many people keep a kiridashi in their camping or fishing kit. As they’re traditionally a carving knife, they’re great for whittling while you camp. They make carving feather sticks for fire-starting a breeze. And they can cut through fishing line, even braided line, without complaint.
Leatherwork
If you’ve done some leatherwork before, you’ve probably noticed that kiridashi are very similar in design and shape to a leather paring knife.
Paring knives are small, simple knives that are used to reduce a piece of leather’s thickness. You hold the leather in one hand, and the paring knife in your other, and you run it down the length of the workpiece to shave away thin strips.
The main difference between Japanese kiridashi and the western paring knives you’d find in your local craft store is the quality of steel. Leather paring knives tend to use low quality carbon steels and strip steels like 1085 and 12C27, which have carbon content between 0.6% and 0.8% and much lower hardness than the Japanese Shirogami and Aogami steels. So Japanese kiridashi are much sharper, and will hold their edge much longer, than a typical paring knife.
Because western leather paring knives and Japanese kiridashi are sold at around the same price point, and are almost identical in shape, kiridashi are starting to become very popular with professional leatherworkers and hobbyists worldwide.
How to Choose and Care for a Kiridashi:
Things to consider when buying
There are a few important things to consider when you’re in the market for a kiridashi knife. While they’re typically very cheap tools, that doesn’t mean they’re disposable. We’re used to utility knives with disposable blades, or mass-produced fixed-blade knives that we replace when they dull. But kiridashi, while cost-effective, are very high quality, and can be used for a lifetime if cared for properly. So carefully consider the following:
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Material: Kiridashi knives are typically made from carbon steel like aogami, shirogami, 1095 and W1. Choose the best steel for your requirements and your budget. Some companies make stainless steel kiridashi, but they’re best to be avoided, as they don’t hold their edges well and won’t last as long.
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Grind Angle: If you’re going to be cutting softer materials like paper, leather, string etc. opt for a kiridashi with a lower grind angle (~20 degrees), but if you’ll be cutting harder materials like wood, metal, bone etc. get one with a higher grind angle (~30 degrees).
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Handle: Most kiridashi don’t come with a handle, it’s simply bare metal. Most of the time, this is totally fine, as they’re meant to be simple tools that don’t require too much care or maintenance. However, if your work requires extra grip, or you have mobility issues that make it difficult to hold on to your kiridashi as-is, you can get kiridashi that come with bamboo handles or cord grips.
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Blade: Kiridashi knives come in various widths, typically ranging from 15mm to 24mm, but down to as little as 9mm and up to 30mm. Consider the tasks you will be using your kiridashi for and choose a blade that is appropriate for your needs.
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Reputation: Look for kiridashi knives from reputable companies or blacksmiths with a history of making high-quality knives or bladed tools. Japanese blacksmiths spend decades perfecting the art of making these simple knives, and that knowledge is typically passed down through multiple generations in the same blacksmithing family. If you buy a kiridashi that was made by a company without much history, or a company that isn’t based in Japan, you will be taking a risk.
- Price: Kiridashi knives can range in price from around $25 to over $100 – with some that were forged by famous bladesmiths like Chiyozuru Korehide currently on the market for over $20,000. Generally, when buying any tool, you should buy the best that you can afford. Set your budget, and then look around to find the best quality, most reputable kiridashi at that price.
If you do your research, and carefully consider all of these factors, you’ll end up purchasing an excellent kiridashi knife that not only meets your immediate needs, but, if properly cared for, will provide reliable performance for the rest of your life.
How to Maintain Your Kiridashi
Maintaining a kiridashi knife is important to ensure that it remains sharp and rust-free. Here are some tips for taking care of your kiridashi:
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Keep It Clean: After each use, wipe the blade with a clean, dry cloth to remove dirt and debris.
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Keep It Sharp: Kiridashi made from carbon steel retain their edges very well. But they still need to be sharpened occasionally. Invest in a whetstone and learn how to sharpen your knife yourself, or take it to a professional knife sharpener when needed.
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Store It Well: When you’re not using your kiridashi, keep it in a dry area to avoid corrosion. If you know you won’t be using it for a while, apply a thin layer of mineral oil or knife oil to the blade to protect it completely.
- Use It Well: Kiridashi knives are designed for cutting. Use your kiridashi only for its intended purpose. Don’t use it to pry open a paint can, don’t strike anything with it like it’s an axe, and don’t hit it with a hammer like you might a chisel.
A good kiridashi is a fantastic investment, and not a very pricey one. You can get a high-quality, well-ground kiridashi made out of Japanese Aogami or Shirogami carbon steel for as little as $25 – and it could last you your whole life.
The fact is, a kiridashi is often the best option in every case it’s recommended for. Whether you’re a carpenter looking for the best marking knife, a carver looking for the best whittling knife, an outdoorsman looking for the best camping knife, a leatherworker looking for the best paring knife, or a botanist looking for the best bonsai knife – in all cases the answer is a kiridashi.
So take a look at our range of kiridashi knives direct from Japan here at Daitool to find something you like.
