Knife sharpening angle depending on the purpose: sharpening devices, master classes

To paraphrase the famous song of Shufutinsky - if knives are sharpened in the house, then there is a man in it. From this article, you will learn what the optimal angle of sharpening a knife should be, depending on the purpose, what kind of sharpeners and sharpening devices are. At what angle to sharpen axes, scissors, kitchen and hunting knives, etc.

Read in the article

0.1 Blade shapes and sharpening angles
- 0.1.1 Manufacturing materials
- 0.1.2 Blade shapes
- 0.1.3 Sharpening Angle Standards Table
- 0.1.4 Determination of the actual sharpening angle
0.2 Knife sharpeners
- 0.2.1 Classic (mechanical) devices and fixtures
- 0.2.2 Sharpeners with control, angle adjustment
- 0.2.3 Additional and alternative devices
0.3 At what angle to sharpen knives, depending on the purpose
- 0.3.1 Kitchen knives
- 0.3.2 Hunter knives
0.4 Sharpening other tools
- 0.4.1 Ax, cleaver, meat hatchet
- 0.4.2 Scissors
- 0.4.3 Chisels, planer knife
0.5 Reviews of various sharpeners

1 Summing up

Blade shapes and sharpening angles

Every knife, regardless of the model, shape and purpose, consists of a handle and a blade. The blade, on the other hand, is heterogeneous in structure and, in turn, has different parts.

Knife sharpening angle depending on the purpose — Blade structure

Main parts:

1 - width;
2 - butt thickness;
3 - the height of the rectangular section;
4 - descent height;
5 - the height of the cutting edges;
6 - the thickness of the cutting edges.

Manufacturing materials

Leaving aside all sorts of exotic and special alloys, we briefly describe the most popular materials for making knives.

Carbon steel. In addition to iron with a certain percentage of carbon, vanadium and manganese are used as modifying additives. Such blades are susceptible to corrosion and can be stained from various aggressive substances. When using these knives in the kitchen, especially at the beginning of operation, the products acquire a light iron flavor, which disappears over time. They are easy to sharpen, but dull just as quickly.

Stainless steel. A complex alloy of carbonaceous iron with chromium with minor additions of nickel or molybdenum. It has increased anticorrosive resistance, but it dulls rather quickly and needs constant sharpening. If the blade has lost its original shine, then it will no longer keep its sharpness, therefore it becomes completely unsuitable for further use.

As a rule, a stainless steel blade has a uniform structure and a characteristic mirror shine.

High carbon stainless steel. The composition, in addition to carbon and stainless steel, includes additional additives (molybdenum, cobalt, vanadium). Due to a significant increase in hardness, more than 55 HRC, the period of maintaining the sharpness of the cutting edge also increases. However, the time before corrosion occurs is somewhat reduced.

The blade made of high-carbon stainless steel is characterized by high performance and aesthetic qualities

Damascus steel. A composite material consisting of alternating layers of mild and hard steel, bonded by forging. It is distinguished by increased strength, due to its heterogeneous structure, does not dull for a long time and forms a kind of saw with micro-teeth on the edge of the blade. If necessary, it is only sharpened along the blade.

Damascus steel blade has a characteristic wavy pattern

Bulat. It is produced by casting using the technology of Anosov, Obukhov and Shvetsov. Differs in the highest performance characteristics. Refers to the knives of the elite class. A hard diamond wheel is required for sharpening.

At first glance, custard steel resembles Damascus steel in its texture, but has significantly improved technical characteristics.

Titanium alloy. It is produced by sintering titanium powder with carbide additives. Sharpening titanium alloy blades requires professionalism and the use of special machines. The use of such knives requires certain skills due to their light weight and extreme sharpness.

Titanium alloy knives are quite expensive, so they are most often produced in a decorative and gift version.

Zirconium alloy (mineral ceramics). Produced by long-term high-temperature firing of workpieces formed by dry pressing. Very sharp, keep sharpening for a long time. However, the blade is quite fragile and is only suitable for cutting soft foods.

Zirconium (ceramic) knives require special care and are rather capricious in operation

Blade shapes

Depending on the profile of the cutting edges and the slope, the following blade edge shapes are distinguished.

1-5 - wedge-shaped;
6 - razor, scalpel;
7 - chisel (Japanese);
8 - chopping Chinese;
9 - bullet.

Sharpening Angle Standards Table

There is a well-established practice of using a certain angle of sharpening of the blade of knives used for various jobs.

Sharpening angle in degrees	Appointment
5-10	Fillet (thinning)
10-15	For fruit, shaving, scalpel, camping knives
15-20	Chopping, cleaver knives
20-25	Boning, for large fish
25-30	Hunting
30-35	Cleavers for meat, large knives for vegetables
40-45	Chopping axes
45-55	Scissors
55-60	Canteens
75-85	Metal scissors

Determination of the actual sharpening angle

To understand what a particular knife is intended for, as well as to determine the correctness of sharpening, it is necessary to measure the angle of the cutting edge.

Measuring the angle of sharpening of the cutting edge

To measure, the knife must be pressed with the cutting edge to a flat surface. Injection (α) calculated by the formula:

α = arcsin (h / L), where

h - height from the base surface;
L - the length of the blade from the point to the place of measurement.

Important! The total sharpening angle is equal to two values of the angles of the cutting edge, that is, - 2α.

The video shows one of the methods for measuring the angle of sharpening of a blade using scissors:

Knife sharpeners

There are two main types of sharpeners:

For sharpening, a certain layer of metal is cut off on the blade, forming the edge of the blade with a given angle. Apexoids and Lansky installations;
For dressing, they do not cut, but only change the angle at the cutting edge. These include: musat, ceramic stones, metal abrasive tools (needle files, files).

In this case, the maximum effect of sharpening is obtained only when used together.

Classic (mechanical) devices and fixtures

Manual mechanical. The market for kitchen tools and utensils offers a variety of hand sharpeners:

with table stop;
vacuum - the same desktop, only with a suction cup;
brass knuckles.

All of these devices sharpen the blade by removing a thin layer from the cutting edge. The working element is plates or rings of hard metal located at an angle to each other. They have from one to three sharpening zones, on which the blade must be processed sequentially.

Varieties of hand-held sharpeners:

1 out of 4

Every man should know this: the angle of sharpening of a knife, depending on the purpose — PHOTO: mysmartbuy.ru

Electric sharpeners. In fact, they are the same mechanical, but with an electric drive. This does not affect the quality of sharpening or the possibility of adjusting its angle. Some of the more expensive models may have a separate dressing section or stepped angle adjustment within a limited range.

Stones. Stones in the form of bars have different surface grain sizes. Depending on the grain size, they can be used for both sharpening and dressing. However, these devices require considerable skill, because to form an angle, the blade must be held manually. Cost ranges from the cheapest coarse household abrasives to professional water, oil and diamond abrasives.

Water sharpening stones with different grain sizes

How to sharpen a knife correctly with a stone can be seen in the video:

Musat. Tool for dressing the edge of the blade. It is used to sharpen kitchen knives that are slightly dull.

Musat is a round file with specific cuts on the surface

Sharpeners with control, angle adjustment

Sharpening devices with the possibility of tight angle control have the same basic design.

Professional sharpener type Apex model Ruixin Pro III

They consist of the following elements:

the bed on which the knife holder is fixed;
a vertical stand on which the sharpening angle is set;
a movable pin on which the whetstone is attached.

The design and features of working with a grinding machine are discussed in the video presented to your attention:

Additional and alternative devices

On Aliexpress and other sites for tools, you can find many technical devices, which are positioned as specific or universal devices to facilitate the process sharpening. However, their effectiveness, and indeed suitability for work, can only be verified by personal experience.

Roller sharpener with adjustable sharpening angle

At what angle to sharpen knives, depending on the purpose

Sharpening of knives at different angles is possible using only professional tools: machine tools or manually on stones. Household sharpeners, which are offered in abundance in stores, are predominantly set at 35-40º.

Kitchen knives

As a rule, household sharpeners provide a sharpening angle of 40-45º, and they also remove too much metal. If a different cutting edge angle is required, use an abrasive stone.

Illustration	Description of action
PHOTO: kitchendecorium.ru	A little water is applied to the whetstone. Then it is recommended to wipe it with a sponge with a drop of dish detergent.
PHOTO: kitchendecorium.ru	We set the sharpening angle according to the pattern, in accordance with the table provided earlier. We remember the position of the blade and during the work we try not to change it
PHOTO: kitchendecorium.ru	The blade is sharpened with smooth movements without undue pressure. The movement is translational, with the blade away from you, from the handle to the edge of the blade, as indicated in the illustration
PHOTO: kitchendecorium.ru	Burrs form on the cutting edge, which must be removed with musat
PHOTO: kitchendecorium.ru	Dressing is performed by translational movements of the musat from both sides of the blade.

Hunter knives

It is recommended to sharpen hunting knives using special sharpening machine tools. Instruction on the example of the model.

Appearance of a professional grinding machine Blitz model

Illustration	Description of action
PHOTO: YouTube.com	We install a sharpening stone in the clamp
PHOTO: YouTube.com	On the compensating mechanism, set a value equal to the thickness of the abrasive bar
PHOTO: YouTube.com	Add oil to a special hole
PHOTO: YouTube.com	Installing the knife on a frame mount
PHOTO: YouTube.com	We expose the angle. On this model, the working range of the sharpening angle is 16-50º
PHOTO: YouTube.com	Reciprocatingly sharpen the blade

Sharpening other tools

In addition to knives, the farm has many other tools that require sharpening. Of these, the most common are meat cleavers or hatchets, scissors and carpentry tools.

Ax, cleaver, meat hatchet

Sharpening an ax on the example of a GPZ model (U8 steel)

Illustration	Description of action
PHOTO: dvamolotka.ru	We form lenticular descents on a plane with an abrasive belt, changing it sequentially from a grain size of 60 to 220
PHOTO: dvamolotka.ru	We fix the ax on the grinder so that the blade and butt are on the same line at an angle of 0º
PHOTO: dvamolotka.ru	Set the cutting edge angle to 10º
PHOTO: dvamolotka.ru	We attach the ax and the sharpening mechanism itself to the table with a clamp
PHOTO: dvamolotka.ru	We carry out the finishing of the cutting edge

Scissors

There are many popular ways to sharpen scissors. For example, many craftsmen claim that scissors will regain their former sharpness if cut with them:

fine-grained sandpaper (from 260 and finer);
thick foil;
dishwashing cloth made of metal shavings.

However, manufacturers recommend the use of files or sharpening stones. Sharpening is performed along the blade, in a back-and-forth motion.

Chisels, planer knife

For sharpening chisels or a plane knife, abrasive (sharpening) stones and special mechanical devices are used. Sharpening of tools on grinding machines with a rotating stone can be carried out, provided that the number of revolutions per minute does not exceed 500-1000 or with constant water cooling, or special grease. Otherwise, the metal will overheat and the edge will come loose.

Device for sharpening chisels on a whetstone

Reviews of various sharpeners

A few reviews about household and professional sharpeners:

Review of the Fiskars knife sharpener:
Read more on otzovik: https://otzovik.com/review_2311856.html

Attribute knife sharpener review:
Read more on otzovik: https://otzovik.com/review_4421249.html

TalleR knife sharpener review:
Read more on otzovik: https://otzovik.com/review_5389313.html

Borner knife sharpener review:
Read more on otzovik: https://otzovik.com/review_8945353.html

Review of the Apex Edge Pro Sharpenig System knife sharpener:
Read more on otzovik: https://otzovik.com/review_2130554.html

It is quite possible to sharpen a knife or scissors at home, even with only the simplest devices. However, if you actively use different cutting tools for different needs, then you cannot do without a professional grinder.

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