How to sharpen a knife? “Sharpening” is indispensable for knives

Indispensable For Knives 01, Shieldon

I think everyone has something to worry about when using a knife. I think it means that the current sharpness will get worse. If you buy a good knife, it will be out of the box, that is, the sharpness in a new state is considerable. However, there is no blade that can maintain its sharpness forever. So I wonder if I can’t use it hard because I’m afraid that the sharpness will be dull.


The technique of sharpening and restoring sharpness is a necessary technique for using a knife without hesitation. However, it seems that there are many people who postpone their first sharpening because they think “what to do if the sharpness gets worse”. So this time I would like to explain about sharpening.


First of all, those who sharpen blades for the first time should start with cheaper blades. A tall blade is probably hard and hard to sharpen, and it’s a shame if you make a mistake and get a big scratch. First, let’s practice with a cheap blade. Opinel is perfect for practicing. It’s cheap and carbon steel is soft and easy to sharpen. Oh, Opinel stainless steel is OK, though. Let’s use and sharpen and use and sharpen repeatedly.


It doesn’t start without this to sharpen

Indispensable For Knives 02, Shieldon

Simple sharpener Next, prepare a whetstone. There is a simple sharpener, and even with this, the sharpness is temporarily restored … The simple sharpener only prepares the surface by “rubbing”, so the sharpness is not durable. Remember to “shave” with a chitin whetstone to make it chitin. Yes, sharpening means sharpening the blade just a little bit to prepare the blade.


Have you ever seen a knife that has changed its shape with Mr. Itamae’s knife? It would have been necessary to have no sharpening every day for many years to become such a thing, but sharpening also means cutting down and reducing it. Whetstones can be classified into three types: “rough whetstone”, “medium whetstone”, and “finishing whetstone”. The number of counts is written on the grindstone so that you can see how rough it is.


Well, it’s a little different depending on the company, but for rough grinds it’s about # 160-600, for medium grinds it’s around # 800-1500, and for finish grinds it’s around # 2000-10000. Generally, “rough grind” is not necessary at first because it is used to repair the blade when the blade is chipped or the cutting edge is dull. First of all, let’s buy “Nakato”.


If it is a general sharpness, it will recover without any problem. If you can afford it, it would be nice to have a “finishing grind”. I recommend Shapton Blade Black Curtain # 1000, which is a little pricey, but if you have this, it’s okay for the time being. You can use it forever.


Let’s sharpen

Indispensable For Knives 03, Shieldon

Whetstone Well, it’s finally how to sharpen. First, let the grindstone absorb water to prepare it. The time to absorb water differs depending on the whetstone, so be sure to check when you wholesale the whetstone. Use a rag or kitchen paper on the sink to prevent the grindstone from moving and prepare for sharpening. First of all, it is important to create a position that is easy to sharpen.

Indispensable For Knives 04, Shieldon

If you look closely at the blade of his knife, which paints the small blade with an oil-based marker, you will find that it is stepped. This small surface is called a small blade. Sharpening this small blade is a common knife sharpening.


For right-handed people, if you hold the knife with your right hand, point the blade toward yourself and place it on the grindstone, and that will sharpen the front side. The surface is the surface that comes up when you use it. The angle is very important for sharpening. Try to keep the same angle at all times. At this time, if the angle is an acute angle (about 15 degrees), the sharpness will be sharp. However, the blade holding becomes worse and the sharpness drops immediately. At an obtuse angle (about 30 degrees), the blade has a good hold, but the sharpness tends to be poor.


But first, let’s sharpen it at the same angle as when it is out of the box. You can see if the small blade is sharpened by applying an oil-based marker to keep the angle with the chitin.

Indispensable For Knives 05, Shieldon

Either way, the trick is to keep this angle right. This is easier with a thin knife and more difficult with thicker knives. So practice with a thin knife first. First, let’s stroke back and forth several times from the base of the handle side. Check if the magic is gone. There is no problem if it disappears cleanly. Let’s stroke at the same angle. At this time, I think the total length of the knife is longer than the width of the grindstone. So slide it toward the tip little by little.


It becomes R as you go toward the tip of the knife, but at that time, move your hand along R and custom a stroke. It’s easy to understand if you apply magic at this time as well. The R part only touches the grindstone a little, so if you make too much stroke, the shape will change, so don’t overdo it!


After stroking several times, touch the edge from the back with your finger. If there is a burr called burr, the table is over. If it doesn’t come out partially, sharpen it and put out burrs. Sharpen the back in the same way and put the burrs on the front again. Then, go back to the table and grind it so that it slides on the grindstone a couple of times lighter than before. That’s it. Those who go to the finishing grind will repeat the same process once more.


Only when it is cut is the blade

Indispensable For Knives 06, Shieldon

Trial cutting after sharpening Oh yeah, you should put a blade on your nails to see if the sharpness has recovered. If it gets caught immediately, the sharpness should have recovered considerably. If you cut the copy paper and it cuts in the air, it will be OK. If you want more sharpness, you will need another whetstone such as a finishing whetstone.


If you sharpen any blade, it will surely become a blade that can be cut. Let’s do it!

Indispensable For Knives 07, Shieldon


Let’s study the shape of the knife. After understanding the structure, the next step is “shape”

Indispensable For Knives 08, Shieldon

This time of the 4th time, after all, the continuation of “What kind of knife should I wholesale?” Last time, the content was about what kind of structure the entire knife is made of, but this time I would like to explain mainly the making of the blade in more detail.


Needless to say, a knife is a “blade”, and its purpose and performance change depending on the shape of the blade (blade part). However, there are considerable individual differences in the outline shape of the blade, and if you explain it, there is no sharpness, so I will omit it this time.


This time I will explain the cross section. In fact, the cross-sectional shape is very important when talking about knives. If you look at the shape of the cross section, you can see the true character as a tool for the knife! The knives on the market are often mixed with boulders, and the design and cross-sectional shape do not match at first glance. For example, some knives are designed as survival knives that are used roughly, but the grind adopts a hollow grind (described later) shape that is not excellent in strength. On the other hand, although it is a cute small knife, some of them have a flat grind or convex grind (described later) shape that is suitable for rough work, and even if they are small, they have specifications that can break firewood like a hatchet. However, the specs that are contrary to the appearance at first glance are obvious by looking at this “cross-sectional shape”!


Even so, unfortunately, even if you look at the specifications table of the knife, there are few that have the cross-sectional shape written on it. The reality is that the user himself has no choice but to judge from the photos and shapes. I think if you contact the knife shop, they will tell you.


But don’t worry. There are only three types of shapes: hollow grind, flat grind, and convex grind! Another thing to raise is a single-edged blade, but since this is a special shape found only in Japanese-style blades, it can be easily identified, so you don’t have to worry about it here. Let’s explain to each.


Hollow grind

Indispensable For Knives 09, Shieldon

Most knives are made with this method of sharpening. It is characterized by its thin and light cross section cut with minus R. There are many advantages such as the thin blade lasting even if it is sharpened, but it is not suitable for rough usage. Mainly suitable for hunting & fishing knives and gentleman’s knives. This shape can be obtained by shaving with a rotating round whetstone, but because of its high productivity, it tends to be adopted even when it does not fit the character.


Flat grind

Indispensable For Knives 10, Shieldon

It is literally flattened. It is durable and can withstand rough usage, but it is heavy. It is mainly used for survival knives and tactical knives.


Convex grind

Indispensable For Knives 11, Shieldon

It is shaved with a bulging R that is the opposite of the hollow grind. It has a high ability to chop wood and is very durable. Of course, it is even heavier than the flat grind. A shape often found in hatchets.



Indispensable For Knives 12, Shieldon

A shape that literally cuts only one side. Very suitable for carving wood. A special shape found in Japanese blades such as cutting knives.


Flat or convex knives are suitable for use such as breaking firewood. But if cooking is the main thing or if you mainly do fine work with a small knife, Hollow Grind may be better. If you know what to look for, you’ll want the next knife again, so be careful (laughs)


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