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How To Sharpen A Convex Edge

Sharpening a convex edge sounds complicated, but it has the same principle as sharpening any edge by having it level to the bevel angle. This guide will show how to sharpen a convex edge either by hand or with the machine.

You can sharpen a convex edge blade with a knife sharpener by placing the Sharpener on a flat surface then inserting the knife between the blades. Once you fully insert the knife, twist your wrist or hand in a clockwise or counterclockwise direction. Do this for 1-2 minutes, and you will have your convex edge blade sharp as new.

If you are using a whetstone, hold your knife blade against the stone, place the edge at an angle between 15-20 degrees to the stone. Start by drawing the blade forward and backward as you gradually increase the sharpening speed; lean forward and press down on both ends of your knife with each pass. After 1-2 minutes, your blade should be well sharpened.

How to Sharpen Convex Edge kitchen knife

how to sharpen a convex edgeThere are several ways to sharpen a convex edge kitchen knife:  .

Using a Sharpening stone

Using a whetstone to sharpen a convex edge blade, wipe your knife clean and then hold it at a 20-degree angle on the stone in the opposite direction of the stone. Push the blade away from you while pulling it precisely along the length of the edge.

You can also use another method by washing the stone in water and drying it before using it for the first time. Use a grinding motion to sharpen the blade, going from side to side in long and slow strokes. If you cannot hold the knife at a consistent angle, hold it near the edge and pull it across the stone with even pressure. This process will also deliver the sharpness you require for your knife.

When sharpening a knife on a whetstone, the bevel angle of each side should be 30 degrees. If the angle is steeper than this, the cutting edge becomes too thin and may break off. If the angle is shallower than 30 degrees, the blade becomes too thick and becomes heavy and difficult to use. 

Don’tDon’t forget to keep the sharpening stone wet while sharpening and do not allow metal filings to accumulate on the stone while grinding.

Using a Sharpening steel

To sharpen a convex edge using sharpening steel, put the convex edge side of the blade on the steel at a 20 to 30-degree angle facing you and away from your body, then begin to sweep it across the steel. 

Sweep the entire length of the convex edge only once, then remove the blade from the steel and repeat the same thing on the other side of the blade.

Sharpen a convex-edged knife by stroking the steel along the length of the blade, not across it.

If you do not maintain the correct angle as you sharpen, the upper primary edge will become straight, and the lower secondary edge will become convex.

Using a sandpaper

You can use sandpaper to sharpen a convex edge that is blunt or dull. First, mark the part you want to grind off while maintaining the blade’s radius, angle, and length. Secondly, grind the metal using a rotating movement so that all sides get even. 

Before grinding with sandpaper, be sure to use a piece of “hard” sandpaper. This type of sandpaper is intended to be used on metal and other hard materials, whereas use softer sandpaper on wood.

It would be fair to keep in mind that excessive grinding will reduce the edges to nothing.

Using a Sharpener

It’sIt’s not advisable to use a sharpener on your convex edge knife as it is built to sharpen at a fixed angle. Using it can take a lot of your time as you will need to gradually sharpen from one angle to another if you want to attain the desired sharpness.

The secret to a fine edge lies in the angle of sharpening. Sharpeners feature a handle with a 100-degree angle. It is best for sharpening 15-20 degree inclusive straight blades. 

Using a sharpening machine

There are various methods and techniques that you can use to sharpen a convex edge like the ones above, but the easiest and fastest way to achieve a wonderfully sharp convex edge is to use a machine designed specifically for that purpose.

Why sharpen convex knives?

A sharp knife is safer, facilitates precision cuts, and allows you to control thin slices of food as quickly as large cuts. To sharpen a convex knife properly requires knowledge, skill, and time.

Convex edges are the most unequal of all edge geometries. It means that they require more work to sharpen or re-sharpen than any other knife on the market. 

It should be sharpened regularly for first-rate cutting performance and to extend their useful life. Convex knives are double-edged, so both sides can be sharpened simultaneously by rotating the blade and then the steel for better sharpening. Convex edges naturally resist digging into food and are easy to keep razor-sharp with a perfect sharpening process.

Advantages of convex knife-edge

Advantages of convex knife-edge

1. It is much easier to use than regular knives for home cooks because they can be very sharp.

2. It is safer to use because the blade is curved and can twist back towards the handle so that the user will cut herself less often.

3. The minimum inflection point of the convex knife edge makes it possible for it to form bend lines.

4. It aids in the precision of the slicing process and is suitable for all types of meat, including poultry, fish, beef, pork, lamb, and veal.

5. It creates a shallower blade angle which allows for less friction on anything you cut with ith it resulting in a faster cut with less effort.

6. The edge ensures a thin and even cut surface. It is perfect for repeated thin sawing and cutting of thin materials.

7. It can roll easily on the board, whereas a straight edge is far more challenging to roll off the board.

8. The edge can give you more freedom in the kitchen and enable you to cook better-looking meals.

9. The edge is nonstick

Disadvantages of convex knife-edge

1. Blades with ample curves have greater weight and may be harder to maneuver.

2. They are more expensive to get.

3. It dulls much faster than the straight edge.

4. They are not easy to sharpen

5. Hard to sharpen because it still leaves a convex edge and quickly gets dinged up after sharpening.

Causes of dull or blunt convex edge knives

Causes of dull convex edge

1. When used with excessive pressure, the edges will rapidly become dull

2. If knife edges are not maintained correctly

3. After using it for a while, it will be blunt or stale.

4. Using it to cut hard object

5. It has a smaller radius and is very hard.

How to use convex knives

It’s a kind of knife that you can use to cut various types of food. The curved path of a convex blade allows for a rocking motion to slice meat and other foods in a single stroke. It is effective when cutting ingredients in a frying pan.

When choosing a convex edge knife, pay attention to the blade’s handle, weight, and size. This way, you’ll end up with one that’s comfortable to use and easy to store.

Also, consider its material: stainless steel, ceramic, or plastic; the latter may feel slightly heavier than other types. It is due to their ability to distribute pressure more evenly.

How to maintain convex knives

How to maintain convex knives

1. Keep your convex knives in a dry, dust-free environment. 

2. Do not store the knife in a damp area for a long time.

3. Convex blades are thinner than other knife styles, and most remain sharp more often.

4. Choose a whetstone that you feel comfortable with; for example, medium grit whetstone is not advisable for beginners.

5. Always wash and dry the knife thoroughly after every use, then wipe the blade with a paper towel dipped in vegetable oil or mineral oil as this will coat the knife with a thin layer of oil that prevents rusting on edge.

6. You can also wipe your knives with a clean cloth barely dusted with flour on both sides of the cutting edge after each use to remove the corrosive acids created by meats and fish.

7. Wash damaged or stained knives with warm soapy water.

8. Never use a grinding wheel, disc, or abrasive object on the blade, as this might damage it.

9. Use slicing action and not chopping action when sharpening.

Convex edge vs. Beveled edge

Before purchasing a knife for cutting, it’s essential to know the difference between a convex edge and a beveled edge.

Convex edge

A convex edge is a concave curve; it creates a more robust cutting edge because it’s slightly tapered from its highest to its lowest point and is also incredibly sharp, so it dulls less quickly than a beveled edge.

The edge is flat and sloped on the bottom to increase strength, with a “beveled” edge in between, while it is designed to be sharpened less frequently than a knife with a comparable beveled edge and can be more easily re-sharpened when necessary.

This type of edge is perfect for heavy-duty tasks such as chopping wood, bone, or fibrous vegetables. The blade is designed for ease of use and as a safety precaution as it reduces the chances that a user will cut their finger as they slice the food.

 Beveled edge

A beveled edge is a slanted or rounded knife edge to form a thin, razor-sharp cutting surface. It is done to both sides of a thin blade, creating a more robust blade with a sharpened base. In contrast, a convex edge is rounded at the edge to create a thin, flat surface that delivers clean cuts.

With a flat beveled blade, you lose the ability to turn the edge further than 90 degrees up or down.

Convex vs. straight edge

Straight edges are also cut-throat razors, open razors, or simply razors. The most apparent and noticeable difference is the shape of the blade. A straight edge razor has an entirely flat cutting surface which allows for an even shave or cut.

A straight-edged knife is more precise and better for cutting thin slices of vegetables or boneless meats. The blade is perfect for making a specific cut by cut motions, while knives with a convex edge are for slicing big pieces of meat such as roasts, tenderloin, and leg of lamb.

Frequently Asked Questions

What is a convex grind?

A convex grind is a one-sided ground bevel. It can be considered a V-shaped grind, where one side features a higher angle than the other. If you want to grind a knife with a flat edge, you would need a straight grind. A convex grind is also helpful for blade applications where slicing and belly cuts are required, such as with a chef knife or meat cleaver.

What angle is a convex grind?

The angle on a convex grind is more than your standard 20 or 24-degree grind. However, depending on the specific knife you are using, it could be anything between 20 and 30 degrees. A convex grind gives you lots of material control on your blade at the cost of slightly less ease of sharpening.

Is a convex edge better?

Convex edge knives are the best hats because they are thinner toward the tip giving you more edge control. A convex edge is an ideal compromise between a straight edge and a serrated edge as it combines the slicing power of a knife with the chopping ability of a saw.

What is a convex grind good for?

A convex grind is excellent for making thin slices or for chopping. A blade with a convex grind is less adept at slicing thick cuts cleanly but is perfect for slicing cooked meat. It is also ideal for chopping because it is the most similar shape to how a knife is used.

How to sharpen a bark river knife?

You are going to need a medium grit diamond stone. Diamond stones are available in grits ranging from extra-fine/fine through extra-coarse/coarse. 

How do you sharpen edges?

The best way to sharpen an edge is by using a knife sharpener. It can be any Sharpener, whether it’s a stone, steel, or electric Sharpener. Begin by getting your blade at the correct angle for your sharpening tool, either steel or stone; stroke along the cutting edge with even steady pressure but don’t wiggle the knife.


Convex edges make cutting different from other kinds of knife blades. Depending on the application, a convex edge can be sharpened to a range of different angles, and that is why we have taken you through how to sharpen your convex edge for a sharper and effective knife.

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