As I said in my first blog these are the basic considerations on selecting the best knife for you. The following are my understanding and observations based on my experience of working with knives, from making, using, and selling, for over 30 years. I am not a metallurgist, so if any of my understandings are flawed, I would love to hear from anyone and learn what I have got wrong.
This an extremely basic guide and not a deep technical analysis. I have quoted a lot of the technical information from published material on sites like Wikipedia.
With the above in mind, within each price point, I have given a score out of 10 for each quality.
The raw material to make the blade.
The most common raw material to make kitchen knives is steel.
Steel is an alloy of iron with typically a few percent of carbon to improve its strength, fracture resistance, and ability to be hardened and provide more ‘parking spaces’ for other elements ‘to park’ on the steel crystal. Many other elements are added to improve other qualities. Manganese to increase wearability, Tungsten to toughen and harden, Cobalt for hardness and corrosion resistance, etc.
As each element is added it may require another element to counter any negative influences, for example, if the steel has more than .8%/.9% Carbon the resulting steel can be brittle so toughening agents like Chromium, Vanadium, etc.. have to be added but too many of certain elements would make the blade hard to sharpen, temper, forge, etc.. So the recipe used is formulated to provide the best steel to meet the makers parameters – price, manufacturing method, hardenability, etc..
For Stainless knives, remember stain-less means it stains less, not stain proof.
- >8% Carbon so the knife can be sharpened to a higher degree and maintain sharpness.
- 14% ≤ 11% Chromium so the edge is relatively easy to sharpen and be acceptably stainless.
- >2% Cobalt will enhance the hardness and toughness of steels of >1% Carbon without the need to increase the Chromium.
- 3% to 4% combination of Molybdenum for rust resistance and Vanadium to increase the hardness and toughness.
For what we traditionally call ‘Carbon Steel’ knives THAT RUST BUT OXIDISE AND ARE MORE BRITTLE THAN STAINLESS ONES BUT MUCH EASIER TO SHARPEN
- >.8% Carbon
- <6% Chromium
- Other elements will add further qualities like wearability, toughness, etc.
- Steel of a recipe to meet the specification of the maker – quality of steel, method of manufacturing, number of layers, thickness, etc. is rolled into sheets and ready to be made into knives.
Method of manufacturing
There are 4 basic methods of making knives.
A blank of the finished size, thickness, and shape of the knife is stamped, or laser cut out of a sheet of steel. The blank is then hardened, bolsters welded, ground, edged, handled, and finished to complete the knife. Generally, this results in a blade that loses its edge quickly if it is easy to sharpen or difficult to sharpen if it stays sharp longer by being thicker and heavier.
There are few exceptions to this rule with stamped knives that stay sharp and easy to sharpen equally to forged blades. These require a higher quality of steel, a better level of heat treatment, more precise grinding, edging, and finishing that is reflected by a higher price.
The main reason for buying such a knife is that typically they tend to be lighter than a forged blade of similar quality.
2. Roll forged
Where a blank of ½ or less the dimensions of the finished knife is cut out of thicker steel of sheet which is heated until it is malleable enough to be put through 2 rollers to create a blade of the thickness and length of the desired length – like rolling out pasta! This is then ground either by hand or a robot to the exact finished shape, hardened, bolsters welded, ground, edged, handled, and finished.
Roll forging squeezes the steel crystals closer and increases the density of the steel resulting in a blade capable of a sharper edge that holds it longer. The number of layers and quality of the core layer and the ability of the maker will dictate the eventual properties of the finished knife.
Most knives made by an artisan and small workshops in Japan are made like this and often referred to as hot forged.
3. Pre forged steel
This is where the steel of the required specification is roll forged by the steel mill into sheets of the finished thickness and density so the maker can simply laser-cut, or dye cut the knives to the final size without the need to forge each individual knife before the rest of the processes, thus increasing production capacity.
This method reduces the cost of manufacturing fully forged knives without losing any of the advantages over roll forged knives but requires larger production to be economical.
Most high-end knives by makers like Kai, Yaxell, Kasumi, Miyabi, etc. are made like this. Major brands use this method so knives with high performance can be manufactured at a lower cost allowing a higher budget for marketing and increasing brand equity. Most knives made in Seki use this method. And referred to as cold forged.
4. Hammer forged
This is where a blank is cut out from a sheet of steel that is of the quality and specification of the maker but of the original thickness that can be forged to the final thickness, dimension, and shape by the blacksmith on a hydraulic hammer before completing by hand on an anvil and the undergoing the other processes of hardening, bolstering, grinding, edging, handling and finishing – all by hand. The hand hammering removes more of the impurities from the steel, further evenness density across the whole length of the blade, and uniqueness of every knife.
This method is used by most individual blacksmiths and very small workshops across Japan and in particular from Sakai, Tosa, Takefu, and Sanjo.
This is where a narrow bar – 3cm to 4cm wide- of the chosen steel is put into a forge to heat the first 6cm to 10 cm of the length and then beaten, initially by a belt hammer and the on an anvil to basic shape before being cut off from the bar and the hand-beaten to the finished shape, size, and thickness. Most Honyaki knives are made from a single layer of steel and then differentially tempered to achieve a hard edge and soft body. There are examples of Honyaki knives made of layered steel to achieve a hard edge and soft body without the need for differential tempering and thus reduce the level of skill required and the cost.
This method of forging is generally reserved for traditional single bevel knives of High Carbon steels like Shirogami and Aogami. Require good sharpening skills and of the highest cost. There are a few Honyaki knives available in double bevel, stainless steel at a more reasonable price. The Suisin Honyaki series is one example.
Material of the handle
Handles come in two basic styles – Japanese and Western. Japanese style handles are attached to the blade by inserting the tang of the knife into the handle and glued in place with epoxy. The balance of these knives without a bolster and full tang tends to be balanced more towards the blade whilst the Western-style handles with a full tang, bolsters and rivets are more balanced for a hold at the bolster/handle.
Entry-level knives have handles of a man-made material like POM (polyoxymethylene) which is economical but more prone to splitting if subjected to different temperatures if regularly washed in a dishwasher. A lot of Western knives, even at the higher end-use this type of handle.
The material of most Japanese knives at the entry-level is Pakkawood – laminated hardwood impregnated with water-resistant substances like Silicon to increase durability, water-resistance, and durability. These are also not dishwasher safe – they generally do not split like POM at the rivets but lose their protective layer and then allow water to penetrate them resulting in an expansion that changes the appearance and eventually leads to splitting. They are also mass-manufactured therefore more economical than solid wood custom made handles.
Higher-end knives have handles made of solid wood and chosen for their aesthetic and rarity are more expensive.
They are also generally of unique shapes and often use exceedingly rare woods like Stag Horn, Cow Bone, Turquoise, Desert Iron Wood, Snake Wood, and Masur Birch in conjunction with Bone, Horn, Silver, Mammoth Ivory, Bog Oak, etc.
The price of a custom handle with Mother of Pearl or Abalone intricate marquetry can be up to £1000 just for the handle. We sell one custom knife with a Platinum Cobweb handle embellished with several ½ Carat diamonds that cost over £100,000!!!
This is purely subjective and has no objective influence on the performance.
The finishing of the knife is the smoothness between the blade and bolster, handle and tang, rivets and handle, the finish of the body (flat or dimpled), mirror finish, sandblasted or acid etched, etc.
This is purely subjective and has no objective influence on the performance.
Well known, established brands normally command a higher price than ones with similar or better performance. Their reputation was built by providing a good product in the first place. So if you are buying the knife from a seller like a department store where the sales assistant does not have detailed knowledge and unable to provide detailed information about the steel, manufacturing, performance and the advantages and disadvantages then it’s better to buy from a well-known respected brand – you’ll pay more money than one from an unknown brand that you know nothing about. But with the confidence that it will be of a certain quality. If buying from a specialist who has detailed knowledge, then you can be guided by the quality and not just brand reputation.
For example, the single-layer stamped steel Global Chroma 18 Series with their seamless metal handles and unique design have been, for many years the most popular Japanese knives across the world – in comparison, our Kyuto Series with a similar aesthetic and seamless steel handle is made of a pre forged 3 layer steel with a higher performance (both in sharpness, edge endurance and ease of sharpening) at almost 30% less cost and half the price of the Global Sanmai Series which is made in the same way with the same material. But if buying from a non-specialist then the Global would a better option the confidence that you are buying a good product.
The level of after sells service costs money. So, if buying from a website that provides no physical place where you can easily go in person to resolve any issue, no phone number where you can speak to someone, with only an email address to communicate via or based in another country, resolving any problem can be difficult, frustrating, time-consuming and often impossible the initial cost may be cheaper. You must accept that a retailer that does provide all these services has to sell at a higher price. You are buying a tool that will be with you for many years and there is a good possibility that you may need some maintenance or remedial work on the knife after or during the many years of its life.