Why do kitchen knives vary in cost?

The cost of kitchen knives can vary considerably, ranging from as little as £6 for a basic chef’s knife to over £1,000 for traditional Japanese blades crafted by a master forger.

A realistic price range for knives used by the majority of professional chefs is closer to between £10 and £200.

But what accounts for this difference?

The following page will look at a range of factors surrounding knife prices. Click on the links below to jump to the relevant subjects:

The downsides of a poor quality knife

There are obvious reasons why chefs do not simply buy the cheapest knife on the market. Some knives are less expensive because the production values are not of the highest quality.

This can result in the following:

  • Chipping. Low-quality steel runs the danger of chipping when under stress. This may occur while in use or as the result of a drop from height, for example, into the sink or on to the floor. Chipping will impair your ability to evenly slice through food, especially meat, as the edge may snag and tear the material.
  • Blunting. Inexpensive knives can often have trouble ‘holding their edge’. This means they become blunt quickly and require constant sharpening, which can wear down the blade and reduce the lifespan of your knife. Some poorer-quality knives can also be difficult to sharpen in the first place.
  • Broken handles. Badly made handles can come loose after repeated use. Material that reacts badly to water can also split and crack, leading to the handle falling off.

Factors that affect the cost of a professional chef’s knife

Knives that fall into the lower end of the pricing range are susceptible to the problems listed above, and generally wouldn’t be considered professional standard. When assessing the differences between professional chef’s knives a number of factors affect cost. These are:

  • Type of steel
  • Production technique
  • Steel quality
  • Material and shape of handle

Type of steel

Steel is produced by taking iron and adding a small amount of carbon and other ‘impurities’ to the mix.

Each knife-making company will use their own brand of steel. How the steel performs and the properties it holds are a result of the different mix of impurities found in the steel. The impurities used in steel making include:

  • Carbon
  • Chromium
  • Vanadium
  • Molybdenum
  • Silicon
  • Nickel
  • Manganese
  • Aluminium

These elements join with carbon to form crystalline molecules called carbides. It is the carbide crystals that affect the hardness and toughness of a steel. The high cost that can be seen with some kitchen knives results from the cost of the materials involved. The addition of certain elements can greatly increase the price.

Steel tends to be separated into 2 categories: carbon steel and stainless steel. However, both types of steel can be harder or softer, depending on the manufacturing process.

Carbon steel — Carbon steel knives are famed for their ability to hold an edge. This type of steel is typically harder than stainless steel, but easier to sharpen to a very sharp edge. However, prolonged exposure to water or acids in food can cause the knives to discolour and rust. Their hardness also makes them more brittle and easier to chip.

Traditionally, kitchen knives made from carbon steel were thought of as the ultimate kitchen knives. With the advent of modern metallurgic practices, it is now possible to produce stainless steel that comes close to the sharpness and strength of carbon steel.

Stainless steel — To make a steel ‘stainless’ requires the additions of 10.5% chromium into the steel mix. The chromium prevents corrosion by producing an oxide layer on the metal’s surface. Increasing the chromium content will increase the steel’s resistant to corrosion.  Stainless steel is considered ‘softer’ than carbon steel, giving it a degree of durability and making it easier to sharpen; however, it cannot achieve the sharpness of carbon steel.

There are types of steel that are known as ‘high carbon stainless steel’. This steel has both a high chromium content and elevated levels of carbon and other elements. This results in a blade that is durable, resistant to corrosion and able to hold an edge better.

Steel quality

The above information is a general guide to the different types of steel and their properties. However, the quality and performance of a steel is not limited to the elements in that steel. Quality can also be affected by the:

  • heat treatment used during construction
  • grain structure of the steel

The optimum hardness range of a steel is a result of the mix of elements used; however, it is when the steel is heat treated that hardness is achieved. Different methods of heat treatment will produce different results. Hence, carbon steel blades are available that are softer than stainless steel blades, and vice versa.

Equally, grain structure can have a big impact. Steel with a large grain structure can be more prone to chipping, while the grain size can also affect how easy a steel is to sharpen. In general, steel with smaller grains wears more quickly but can be sharpened to a keener edge. 

Grain structure is, in part, down to the elements used in the steel.

Production technique

There are generally three methods of shaping a metal into the required kitchen knife design:

Forging

The steel is heated in a forge to a temperature at which it is malleable and then hammered and beaten into the desired shape.
Stamping

A steel die (mould) is used to stamp out the shape of a knife from a sheet of steel. The blade is then ground to the required specifications. Most mass produced knives are produced using this method.
Stock removal

Similar to stamping, this method involves the removal of material from a section of steel. The dimensions are produced through the grinding of the steel, rather than by reshaping it using tools. Many bespoke handmade knives are produced like this.

In the past, forging a knife was considered the superior option, as the process acted to distribute the impurities throughout the metal, reducing the chances of weak spots occurring. However, with modern steel-production methods, as well and the latest manufacturing techniques involved in stamped kitchen knives, these differences have been greatly reduced.

Kitchen knives at the higher end of the price range are often hand forged on a small scale. Addition costs also arise from the extra labour involved in hammering and folding together high numbers of steel layers.

Judging steel quality

When judging the quality of a kitchen knife, it is useful to compare the following six practical properties of the steel involved:

Hardness

The ability of a steel to resist becoming stretched or deformed when put under stress. Hardness is measured using the Rockwell scale; specifically, the Rockwell test measures the depth of penetration from a load attached to a protruding tool of a specific size and shape.

There are several Rockwell scales, the most common being the "B" and "C" scales. Softer metals are tested using the B-scale. These include softer steel as well as aluminium and brass.

The C-scale is used on harder materials.  This uses a diamond cone as its indenting tool.

Hardenability

Describes how easily a material can be hardened when cooled from a high temperature using a rapid thermal treatment. When steel is cooled quickly from a high temperature it forms a crystal structure known as martensite. It is this material that gives steel much of its toughness.

Toughness

Cracks can be a problem with kitchen knives. The resistance of a blade to cracking is known as its ‘toughness’. A steel that has an even grain size is tougher than one that features large grains distributed throughout; cracks can appear around these grains, especially around carbide crystals.
Edge Retention

This refers to how long a knife edge will stay sharp.
Wear Resistance

The ability of a knife to resist abrasion or erosion is known as its wear resistance. The size of the carbides contained in the steel directly affects its ability to resist wear. Large carbides are harder to dislodge and, therefore, create more wear-resistant steel.

Handles

The means by which handles are constructed and the material chosen both play a part in the cost of a kitchen knife.

The handles of kitchen knives were traditionally made using wood. However, modern materials and construction techniques mean that wood is less frequently used; the porous nature of wood meant that some handles were prone to swelling and splitting, while cracks that may appear could harbour germs and bacteria.

In modern times, handles can be found in a number of materials including rubber, composite wood treated with resin, and even metal.

Much effort has been put into creating handles that balance well and fit perfectly into the hand. The time and money spent on revolutionary new handle designs can increase the cost of a knife.

Conclusion

Many factors contribute to the cost of a knife, be it the composition of the steel, the heat treatment techniques used, the design of the handle or the time and effort put it to the production method.

Some knives are simply expensive because they fulfil the dual purpose being both an effective kitchen knife and a beautiful object to be treasured.

Sometimes expensive knives aren’t always the best option. For less important tasks, there is something to be said for opting for a less expensive blade — one that can be quickly replaced when it reaches the end of its lifetime.

In the end, it is down to knowing the brands available, following recommendations and trusting that the manufacturer knows how to properly produce the knife using the highest quality materials.

For more information on knives, click on the links below:

29 November 2017

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