Kitchen Knife Anatomy
Kitchen knives are essential tools for any home or pro chef, but all knives are not equal. Different styles from around the world offer different advantages and disadvantages in terms of their shape, design, material and more. In this page, we will explore different styles of kitchen knives and look at the anatomy of western-style kitchen knives as compared to those found in Japan. We will compare designs, materials used and other elements so cooks can make an informed choice on which style of knife they should use. So whether you're just starting out or have been cooking for years, read on to learn what makes each knife unique.
German Double-Bevel With Full-Bolster
German Double-Bevel With Half-Bolster
Japanese Double Bevel With Western Handle (Only Bolster)
German Double-Bevel With No Bolster
Japanese Double Bevel With Wa Handle
Japanese Single Bevel With Wa Handle
Unibody Hollow Handle
Some kitchen knife designs are integral, meaning the whole shape of the knife is made of the same piece of metal. Unibody designs do not have a tang at all, and feature a hollow handle.
Knife designs vary within brand, maker, or country of origin. Western handles customarily include a Bolster, and their design will change with the maker's prerogative or cultural predispositions. Traditional Japanese Wa-Handles (Hidden Tang) do not include a bolster; they typically have a Ferrule (Collar) commonly made from wood or bone. Bolsters are steel and can be integral or forge-welded. They have a taper towards the blade, which can be blunt or gradual. They are located where the handle meets the blade, helping serve as a connecting point. Generally, their purpose is to add weight and balance at the fulcrum point. There are different types of Bolsters, and they serve other purposes. It’s a matter of preference for the user on what type of handle is best for their work.
A full-Bolster is integral, meaning it is forged from the same piece of steel that the knife is made of. Its design drops from the handle to the heel, creating a finger guard. The Full-Bolster also offers strength which is beneficial when the knife may be used with a heavy hand or used on hard food products. This extra strength comes at a cost since the finger-guard is thicker than the blade and cutting edge. It inhibits the ability to sharpen the cutting edge at the heel properly. It’s recommended to carefully remove a micro amount of steel from the bottom of the guard to match the amount of steel removed when sharpening. Otherwise, the blade will form a dip in the cutting edge, and the knife will not perform as intended.
Half-Bolster, Semi-Bolster, Demi-Bolster
A Half-Bolster is also integral, meaning it is forged from the same piece of steel that the knife is made of. Its design drops down from the handle only halfway and allows for strength in the blade but enables full access to the corner of the heel when sharpening.
A knife with a bolster that does not drop down keeps the profile or silhouette of the handle. It can be either forge-welded onto the blade from separate pieces or integral. This design offers moderate weight and enables full access to the corner of the heel when sharpening.
A common design for western handles is to exclude a Bolster altogether. In the past, knives without a bolster were considered to be ‘cheap.’ But, with innovations and the progression of materials and manufacturing processes, high-quality knives are often produced without a bolster, especially among small independent knife-makers who often use exotic woods, which are commonly a heavier material, not requiring the added weight.
A knife's tang is the portion of the blade that extends into the handle. There are different types of tangs. Different cultures have produced different styles. Tangs can be important in production costs, balance, weight, and feel.
Full Tang designs are classically found in German and Western knives. Although today you will see Western handles on Japanese knives. The tang extends fully to the butt of the knife and matches the silhouette of the handle. You can see the tang in between the handle materials. Metal pins help affix the handle material to the tang. More metal means more weight, especially if the design includes a metal bolster.
Half Tang designs will also be found in Western handle designs. The tang stops at the halfway point, not fully to the butt, and should be affixed with metal pins. You will find this design feature in lower-priced knives. Ultimately, its construction is not as strong as that of a full tang.
Hidden Tang designs are common in traditional Japanese designs. The tang is tapered and extends into the handle, stopping shy of the butt. It's in the name; the tang is fully hidden from view. A hidden tang handle overall makes the knife lighter weight.
No Tang - Hollow Handle
A Hollow Handle does not have a tang. It is formed from steel then welded to the blade. Hollow Handles can incorporate a bolster which is typically hollow as well. Higher quality designs such as Global, produced by Yoshikin, have sand inside the handle to achieve good balance.
Bevels and Forging Construction
Understanding a double-bevel edge versus a single-bevel edge is pretty straight forward. A bevel is the surface that has been ground, forming the knife’s cutting edge. When looked at closely, you can see the angle on both sides of the blade or only one. If both sides have an edge, then it’s a double-bevel knife. If there is only one, then it’s a single-bevel blade. The bevel may be ground in a variety of angles.
Stamped Vs. Forged Vs. Stock Removal - Which Is Better?
We believe a more appropriate question is “What is better for the user?”. We don’t believe in absolutes, and for this topic, advancements in modern metallurgy and improved manufacturing techniques have blurred the lines. There is such a broad range of people who use knives, from home cooks to professionals. The work required of them is also broad. Other considerations such as budget, skill set, and personal predilections will play a part in making an informed decision. Generally and historically, it was widely accepted that forged knives are very high quality and stamped knives are lower quality. That’s not always the case in today’s world. It’s possible to purchase a quality knife that functions well that is stamped. We suggest that no matter what ‘level’ you choose, purchase from reputable brands & companies. This will ensure you buy a quality product that lasts for years to come. Stock removal can produce very good knives, but takes less expertise in shaping compared to forging.
Forged knives are made from a billet of steel by heating the metal in a forge or furnace until it is glowing, then hammering the steel into shape on an anvil. The hammering & shaping can be done by hand, machine (power hammers & hydraulic presses), or a combination of both. A blade can be forged from a single billet (mono steel), or from multiple layers which are forge-welded together, producing Sanmai or Damascus forging constructions. Steps are then taken to aneal, quench, and heat-treat the blade. The blade and tang are then refined by grinding or sanding, attaching a handle, then sharpening.
Stamped knives are made by cutting out the shape of a knife from a sheet of steel using a cutting die, laser, or water jet. Typically, multiple knives are cut at once. Very much akin to a cookie cutter. The stamping process never allows for an integral bolster since the sheet of metal is thin. When a knife is forged, the bladesmith can choose to shape and hammer a bolster into the design. Little to no grinding and refinement is required for stamped knives before heat treatment. Handles are attached, then final sharpening is implemented.
Stock Removal is simply removing away material from steel bar stock. Makers will use a myriad of tools such as files, grinders, belt sanders, saws, or abrasives. Essentially, carving out the thickness, bevels, and shape of a knife, as opposed to forging a billet into shape. It is important to note the distinction of a maker versus a bladesmith, since less skill is required for stock removal. Although, to produce a high quality knife by stock removal, it’s critical that the maker has a good working knowledge of metallurgy to accomplish a high-level of annealing, quenching, and heat treating (thermal cycling). A deep understanding of overall design and balance will further help produce a quality product. Stock removal is a great way to get into the art and science of knife making and smithing.