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How to sharpen a knife? A guide to knife and pocket knife sharpening accessories
How to sharpen a knife to improve its sharpness while not damaging the cutting edge? Many people using kitchen knives, pocket knives, and other types of blades ask themselves this question. Choosing a sharpener alone is not enough, as technique, pressure control, and the correct sharpening angle are equally important. Well-chosen accessories allow for quick sharpening, but if used incorrectly, they can round the edge or remove too much material.
In this guide, we explain how to sharpen a knife and how to choose accessories based on the type of blade and your skills. We discuss the most popular sharpening surfaces, including stone, diamond, ceramic, steel, and tungsten carbide. We also show the differences between V-type, rod, compact, electric sharpeners, and sharpening systems. Separately, we explain how to sharpen a knife on a stone and at what angle to sharpen knives.
Types of Knife Sharpeners – Sharpening Surface
When choosing a sharpener, the shape is not the only important factor; the material responsible for grinding the steel is crucial. The sharpening surface determines the speed of work, sharpening precision, the amount of material removed, and the final effect. The most common are stone, diamond, ceramic sharpeners, and models made of tungsten carbide.
Stone Sharpeners
Stone sharpeners are among the most classic and precise tools for sharpening knives. They can be made from natural or synthetic stone, and their effectiveness mainly depends on the grit, i.e., the graininess of the surface. The lower the grit, the more the stone grinds the steel. The higher it is, the more it smoothens and finishes the edge.
The grit of the stone defines the graininess of the surface and affects the intensity of sharpening. Low grits are for heavily dulled or slightly damaged blades, medium for basic sharpening, and high for smoothing and polishing the edge.
- 200–600 — for heavily dulled knives, initial sharpening, and edge repair,
- 800–1200 — for basic sharpening of most kitchen, tourist knives, and pocket knives,
- 2000–3000 — for smoothing the edge after sharpening,
- 5000 and more — for very precise finishing and polishing of the blade.
Sharpening stones often require pre-soaking in water or the use of an appropriate oil, depending on the type of sharpener. During work, you must manually control the angle of sharpening the knife, so this method requires some skill, but it allows you to achieve a very good result.
Diamond Sharpeners
Diamond sharpeners use a surface coated with synthetic diamond particles. They are very effective because the diamond is an exceptionally hard abrasive material. This makes it well-suited for handling high-hardness steels, which can be more difficult to process on classic stones.
Their great advantage is the quick pace of work. A diamond sharpener is useful when the knife is clearly dulled or needs the cutting edge restored. Depending on the grit, it can be used for aggressive sharpening as well as gentler honing.
What to watch out for?
- excessive pressure can remove too much steel,
- coarse grits leave an aggressive, less smooth edge,
- with delicate knives, work carefully and without haste.
Ceramic Sharpeners
Ceramic sharpeners are primarily for regular honing and smoothing of the cutting edge. The ceramics are hard but less aggressive than diamond, making them suitable for ongoing knife maintenance and as a finishing stage after stone or diamond sharpener use.
Ceramic sharpening surfaces come in, e.g., rods, V-type sharpeners, compact models, and sharpening systems. It's worth choosing them when the blade isn't heavily dulled, and the goal is to improve sharpness, smooth the edge, and achieve cleaner cuts.
Tungsten Carbide Sharpeners
Tungsten carbide sharpeners are easy to use and allow for quickly improving the sharpness of a knife. In such models, the blade is guided through a special slot with hard plates that remove a thin layer of steel and form the cutting edge at a fixed angle.
This is a good choice for those who want to quickly hone a kitchen, work, or tourist knife without learning more demanding techniques. However, they need to be used carefully, as tungsten carbide works quite aggressively. With too frequent use, it can excessively grind the blade, so for more expensive or precisely ground knives, it is better to choose a stone, ceramics, diamond, or a sharpening system.
What Sharpener to Choose? - Division by Form
In addition to the abrasive material, the form of the sharpener is also important. Its construction determines whether it will be easy to maintain the sharpening angle, whether the tool will be suitable for field use, and how much control the user has over the entire process. A different sharpener would be suitable for quickly honing a pocket knife on a campsite and a different one for precise sharpening of a kitchen or outdoor knife at home.
| Type of Sharpener | How does it work? | Best Application | Advantages | Limitations |
|---|---|---|---|---|
| V-Type Sharpener | The blade is guided between two elements set at a fixed angle. | Quick honing of kitchen, tourist, and utility knives. | Easy operation, does not require much skill, helps maintain the angle. | Less precision than a flat stone or sharpening system. |
| Rod Sharpener | The knife is guided on a steel, ceramic, or diamond rod. | Regular edge maintenance and smoothing. | Lightweight, quick to use, good for daily maintenance. | Requires manual control of the sharpening angle. |
| Dog Bone Sharpener | A small, often ceramic sharpener shaped like a bone. | Pocket knives, folding knives, and smaller outdoor knives. | Compact, lightweight, easy to carry in the field. | Not ideal for heavily dulled blades. |
| Electric Sharpener | Mechanical abrasive elements sharpen the knife when the blade is inserted into a guide. | Quick sharpening of multiple knives, mainly kitchen ones. | Very fast, convenient, repeatable. | May remove more steel than manual methods. |
| Compact Sharpener | Combines small size with one or more sharpening surfaces. | EDC, camp, survival, car, tourist backpack. | Mobile, practical, good for emergency honing. | Does not replace precise sharpening on a stone or system. |
| Sharpening System | The knife is clamped in a holder, and the sharpening element is guided at the chosen angle. | Precise sharpening of folding, outdoor, and kitchen knives. | High control, repeatable angle, very good effect. | Requires more time and is less mobile. |
For quick and simple honing, V-type sharpeners, compact models, or those with tungsten carbide will work best. For regular maintenance, rod and ceramic sharpeners are a good choice. For precise sharpening, it's worth choosing a stone or a sharpening system, especially if the knife is more expensive, made of harder steel, or requires maintaining a specific sharpening angle.
How to Properly Sharpen a Knife with a Stone Sharpener?
Sharpening a knife on a stone requires more patience than using a simple guided sharpener but gives you excellent control over the result. Three elements are crucial: the appropriate grit of the stone, stable guiding of the blade, and a constant sharpening angle.
Before starting, check whether the stone requires soaking in water, using oil, or working dry. Waterstones are typically soaked for several minutes until they stop releasing intense air bubbles. Then, place the stone on a stable, non-slip base.
Step by Step Knife Sharpening on a Stone
- Prepare the Stone
Check if the stone requires soaking in water. Then place it on a stable, non-slip surface. - Select the Grit
For a heavily dulled knife, choose a lower grit, e.g., 400–600. For standard sharpening, 800–1200 is usually enough. Finer grit is for smoothing the edge. - Set the Sharpening Angle
Place the knife on the stone at a constant angle. In kitchen knives, this is usually about 15–20° per side, and in outdoor and work knives, about 20–25°. - Guide the Blade on the Stone
Move the knife smoothly and evenly from the blade base to the tip. Do not press too hard — a steady angle and regular movement are more important than force. - Sharpen the Other Side
After a few strokes, turn the knife and repeat the sharpening on the other side. Try to make a similar number of passes on both sides. - Smooth the Edge
Finally, use a finer grit and make a few light strokes on both sides of the blade. This helps remove minor irregularities and improves cutting quality. - Clean and Check the Result
Wipe the blade and stone of sharpening residues. Check sharpness by cutting a piece of paper or a thin piece of string. Do not check the sharpness with your finger directly on the cutting edge.
For beginners, maintaining a constant angle is the most challenging. A simple angle guide or practicing on a cheaper knife before moving on to sharpening a better model may help.
At What Angle to Sharpen a Knife?
The sharpening angle of a knife influences the sharpness, edge durability, and the way the knife works in the material. A smaller angle provides a thinner, more aggressively cutting edge, but it is more susceptible to damage. A larger angle increases the blade's durability but may reduce cutting precision.
In practice, the sharpening angle is often given for one side of the blade. This means that if a knife is sharpened at an angle of 20° on one side, the full angle of the edge is about 40°.
| Type of Knife | Recommended Sharpening Angle | Characteristics |
|---|---|---|
| Kitchen Knives | approx. 15–20° per side | Good for precise cutting but requires more careful use. |
| Folding Knives and Pocket Knives | approx. 18–22° per side | Universal range for everyday use. |
| Outdoor and Survival Knives | approx. 20–25° per side | More durable edge for outdoor work. |
| Work Knives | approx. 22–30° per side | Greater durability for heavier tasks. |
For most users, the safest choice is to stick to the range of 20–25° per side for outdoor knives and 15–20° per side for kitchen knives. It's not always necessary to aim for a perfect value to the nearest degree. More importantly, maintain the same angle throughout the sharpening process.
Knife Sharpening Accessories in the MILITARY Offer
The MILITARY offer includes knife sharpening accessories tailored to different needs — from simple sharpeners for quick honing, through stone, diamond, ceramic, and electric models, to more precise sharpening systems. This way, you can choose equipment for kitchen knives, pocket knives, multitools, as well as outdoor or work knives. When choosing, pay attention to the type of sharpener, grit, ease of maintaining the angle, and whether the accessory is for regular maintenance or more precise sharpening.
