Knife Anatomy

Knifemaking is a tradition that dates back to the beginning of humans, they are arguably our first tool and as such have had thousands of years of design put into them. Due to this many say there is nothing new under the sun when it comes to knife design. The positive to this is that we have hundreds and thousands of different knife designs that have been tried and tested through the years, and likely the knife you want to tackle next has plenty of thought already given to it for you to base your own ideas and concepts behind.

Knife Anatomy

Every part of a knife has a name. Following you will see two common styles or approaches to knife construction.

A Hidden Tang where the Tang of the knife is embedded inside the handle. The other being a Full Tang where the tang of the knife is the full width and profile of the handle, fitted with scales to create the thickness and shape.

Anatomy of a hidden tang knife

This knife was designed by Master Smith Shawn McIntyre.

Edge: The sharpened part of the blade at the bottom of the knife.

Point: The very tip of the knife.

Choil: The transition between the blade’s edge and the ricasso.

Plunge line: The transition between the bevel of the blade and the flat face of the ricasso.

Bevel: The facet of the blade where it has been ground or forged into two planes that meet at the sharpened edge – discussed below in Bevel Geometry.

Ricasso: The transition space between the guard and the blade. This should be flat and parallel on the sided and is often used as a reference surface during making the knife.

Land or Flat: The flat space extending from the ricasso along the sides of the blade. This is unground and unbevelled, with the size and shape varies a lot depending on the Bevel Geometry.

Spine: The back of the blade. Depending on the style of the knife, this can be flat with crisp edges, rounded to provide user comfort, or faceted as in many Japanese styles of blade.

Guard: Usually made from metal the guard is a transition piece from the handle to the blade and protects the user’s hand from slipping forward onto the blade and anything slipping from the blade into the user’s hand.

Spacers: Often a decorative element with materials of contrasting colour. They can be ground flush and polished with the handle and guard or finished separately with coining or decorative filework.

Tang: The tang is the bar of metal that extends from the ricasso through the guard and spacers into the handle, often secured permanently with epoxy and a single pin. It is important that the tang is not made too short, thin or lacking in width so as not to create weakness in the blade. Your knife is only as strong as your tang.

Pin: The pin provides a mechanical fastener to hold the tang in place inside the handle material, often in combination with epoxy, though many Japanese knives are secured in their handle with a single pin of bamboo. Commonly made from metals like stainless steel, nickel silver, brass, copper, and in recent times materials composite materials like G10 and micarta.

Handle: commonly made from hard, dense, durable species of timber or synthetic materials like micarta. Being that the handle is where the user interfaces with the knife, its size and shape are very important, especially taking into account the knife’s intended purpose.

Lanyard Hole: A lanyard hole is often a metal tube that passes through the handle, though it can also be an unlined hole. They are an attachment point for a cord or a decorative fob displaying knotwork or a bead, or when unadorned to slip your hand through so you can’t drop the knife.

Butt: This is less a specific component than a general area. Features like bolsters or a pommel or tang nut may be located here.

Effective grip length: This term is used for the measurement of the actual useful handle grip length you have on your knife. Knives can have what seems to be a long handle that’s limited by strange guards and overly large and cumbersome handle swells, deep finger choils, or sub-hilts. This measurement takes the inside radius of both and tells you how much you have to hold onto.

Handle drop: The measurement that refers to the amount the handle has dipped from the back. Common in hunting and utility knives.

Anatomy of a full tang knife

This knife was designed by Mastersmith Shawn McIntyre.

Please note this knife includes some advanced features.

Clip/Swedge: The clip or swedge is a drop in the profile of the spine that lowers the tip. This is often to bring the tip closer to the centre of the handle but the amount of drop can vary greatly. It may be dropped level with the edge in a Wharncliffe style blade or the swedge may be raised from the spine and not drop the point at all. A clip may be unbevelled, bevelled but not sharpened where it is usually called a false edge, or bevelled and sharpened.

Recurve edge: A recurve edge concaves the cutting edge in on itself. Used for particular cutting tasks. Can be made slight or highly aggressive depending on the design choice.

Distal Taper: Distal taper refers to a gradual taper – reduction in thickness – from the ricasso to the tip of the blade. This is a somewhat advanced feature requiring a fair amount of skill to get the taper even on both sides of the blade. Distal taper is not a common feature on knives, but an essential feature on most designs of sword in order to give the blade proper balance.

Handle Scales: Handle scales are attached to the sides of the full tang handle giving it thickness and shape. Commonly made from timber or synthetic materials. These are usually attached with both pins and epoxy, or mechanical fasteners like countersunk bolts.

Liners: Liners are used to provide a contrast between the handle scale and the tang. They can also be used as a structural component if your full tang handle is made from multiple pieces. Often made from G10 or micarta or thin sheet metal like brass, copper, or bronze.

Bolsters: Similar to a guard the bolster is a transition between the handle and the blade. Often made from metals like brass and stainless steel, and attached with pins that have been peined end ground flush to permanently secure the bolsters.

Full Tang: A full tang blade is made from one solid piece of metal with its edges exposed along the whole length of the knife. This is a very simple and durable way of making a blade especially with the stock removal method of grinding the blade from a bar of steel.

Tapered Tang: A full tang that also has a distal taper from the ricasso to the butt. This technique is more advanced and requires skill to get the handle scales lined up with the pins on a tapered surface rather than a flat parallel surface. Tang tapering is typically done for weight reduction and to improve balance.

 

Bevel Geometry

Each of these ‘grinds’ refers to the cross-sectional shape formed when grinding the bevels onto the blade, which terminate in the cutting edge. They give advantages and disadvantages and will make the finished blade more or less suitable for performing different tasks.

1. Hollow grind – This is a concave bevel, ground using a wheel. The diameter of the wheel used determines the radius of the hollow, and in combination with the depth of the hollow and the thickness of the blade, the height of the bevel. In historical or traditional methods a stone wheel would be used; in the present day, a contact wheel on a belt grinder is used. A hollow grind produces a very sharp edge, good for slicing but not necessarily as strong as other grinds. High-end kitchen knives may have a very subtle hollow grind on a section of the blade to aid in food release, all or most of Bob Loveless’ highly utilitarian knife designs were hollow ground, and straight razors have a deep hollow grind on a smaller diameter wheel which aids greatly in sharpening.
2. Full flat grind – The bevel is the full height of the blade, tapering all the way from the spine to the edge. This makes the bevel as acute as it can be relative to the thickness of the blade giving excellent cutting geometry. Full flat grinds are common on kitchen knives, bowie knives, hunting knives, filleting knives, and slip joint folders.
3. Sabre grind – Similar to a flat grind except the bevel starts below the spine, often 1/4, 1/3, or 1/2 way down the blade. Leaving a portion of the blade at full thickness adds strength, rigidity, and mass. Sabre grinds are common on modern folding knives, tactical/military, and outdoors or survival knives.
4. Chisel grind – Bevelled on one side like a chisel, flat or very slightly hollow-ground on the other. Commonly used on traditional Japanese kitchen knives. This greatly reduces the total angle of the edge giving a profile twice as acute as a blade with two bevels of the same angle. This allows a thick and robust blade to be extremely sharp, furthered by having no secondary edge bevel. A chisel ground blade makes sharpening very easy since there is only one bevel to work on. Knives that are chisel ground come in left and right-handed varieties, depending upon which side is ground.
5. Scandi grind – A sabre grind without a secondary edge bevel is called a Scandi grind, as in Scandinavian, since they are a common feature on Scandinavian knives like the Finnish puukko or knives manufactured by Mora in Sweden. Scandi ground blades are popular on bushcraft knives and wood carving knives, especially for working with green wood. They can be extremely sharp since there is little or no secondary edge bevel, but the grind height is often only 1/3 or as little as 1/4 the height of the blade making it relatively obtuse and less suitable for fine slicing.
6. Convex grind – Rather than flat bevels that taper in straight lines to the edge, the taper is curved with a gentle radius – the opposite manner to a hollow grind. This keeps more mass on the blade than a flat grind while eliminating the shoulder on a sabre grind which can create drag when cutting. A convex grind can also come to an edge with no secondary bevel, like a scandi grind. Convex grinds are usually only found on handmade custom knives and high-end production knives due to the difficulty of getting a machine to produce the gentle radius on the bevel – they are almost always ground by hand on a slackbelt or rotary platen.