Friday, November 5, 2010

Knife Glossary of Terms

General Terms

Back - The back of the blade is the opposite side of the belly, for single edged pocket or bowie knives this would be the unsharpened side. The back can contain lashing grommets, jimping, it's own edge or false edge, and serrations.

Belly - The belly is the curving part of the blade edge. Bellies enhance slicing and may be plain or serrated. One note, the point of the knife becomes less sharp the larger the belly is. When choosing a knife you should decide whether penetration or slicing is the most important, and keep the design of this part of the knife in mind.

Bevel - The bevel is the sloping area(s) that fall from the spine towards the edge and false edge of the blade.

Blade - See Blade Steels (below) .

Blade Spine - This is the thickest part of a blade. On a single-edge, flat-ground bowie knife, the blade spine would be at the back of the blade. For double-edged blades, the blade spine would be found right down the middle.

Butt/Pommel - The butt, or the pommel is the very end of the bowie knife. The butt/pommel will be found in different shapes, depending on what features it was designed to implement. Some flat metal butts/pommels are good for hammering. There are pointed metal butts/pommels, known as bonecrusher pommels used on combat fighting knives, combat tactical knives, combat survival knives and large bowie knives. They can be decorative, or contain a lanyard hole. Some butt/pommels are designed to be removed to be able to store items in the handle or may contain an additional smaller blade or tool.

Butt Cap
- A metal cap fitted over the pommel is referred to as a butt cap.

Choil - The choil is the unsharpened part of the blade. It is left at full thickness like the blade spine and is found where the blade becomes part of the handle. Sometimes the choil will be shaped (An indentation) to accept the index finger. It also allows the full edge of the blade to be sharpened.

Crink - A crink is a bend at the beginning of the tang that keeps multi-bladed pocket knives from rubbing against each other.

Edge
- This is the sharpened side of the blade. Blades will have a single or double edge (or dagger style) depending on the design.

Escutcheon - this is a small pin or piece of metal attached to the handle for engraving, branding, or just decoration.

False Edge - Widely used on military and combat fighting knives, a false edge blade is an additional bevel on the back of the blade enhancing the blade's point. This edge can be sharpened or not. The false edge can also be used for heavier cutting that might be damaging to the cutting edge.

Guard - The guard is a separate piece of metal attached between the blade and the top of the handle to protect hands from the edge during cutting.

Hilt - The entire handle, including the butt/pommel and the guard.

Kick - The kick is found on a pocket knife, usually Boker pocket knives, and is the projection on the front edge of the tang, the blade rests here in the closed position and keep the front part the edge from hitting the spring.

Lanyard Hole - This is a hole to fit a lanyard, rope or carrying implement through.

Lashing Grommets/Jimping - These terms refer to notches that are designed into the back lower part of the blade for better thumb control.

Mark Side - This is another pocket knife term and is the side of the blade with the nail mark.

Nail Mark/Nail Nick - On a pocket knife blade the nail mark is a groove cut into the blade so that it can be opened using your fingernail. Most Case pocket knives use this method of opening the blade.

Obverse Side - The obverse side is the front or display section of a knife.

Point - The tip of the blade. For more information see Blade Shapes.

Pile Side - The reverse side of the blade, opposite of the obverse side.

Pocket Blade - This is the largest blade on a multi-bladed knife.

Pen Blade - The pen blade is the smallest blade on a multi-bladed knife.

Quillon - The quillon is the area of the guard that extends past the section surrounding the tang and is the most protective part of the guard.

Ricasso - The ricasso is the flat section of the blade between the guard and the start of the bevel. This is where you will most often find the tang stamp.

Scales - The scales are pieces that are attached to a full tang to form the handle.

Scrimshaw - Scrimshaw is the art of etching decorative designs into ivory or simulated ivory handles.

Serrated Edge - Serrations are a set of "teeth" or notches on the back or front of the blade to aid in cutting.

Swedge - A swedge is a bevel on the back of the blades.

Tang-Stamp - This is an imprinting that can show style number, collector's number, manufacturer's name. This is normally located on the ricasso.


Handle Materials

STAG
Derived from naturally shed deer antlers. When exposed to open flame, stag takes on that slightly burnt look. Very elegant material for pocket knives and gentlemens folding knives.

BONE
Derived from naturally deceased animals. Bone is usually given a surface texture, most commonly in the forms of pickbone and jigged bone. Bone can be dyed to achieve bright colors (e.g. green, blue, and black). This is the most common handle material for pocket knives.

G-10
A fiberglass based laminate. Layers of fiberglass cloth are soaked in resin and are compressed and baked. The resulting material is very hard, lightweight, and strong. Surface texture is added in the form of checkering. G-10 is an ideal material for tactical folding knives or fighting knives because of its ruggedness and lightweight. It is usually available in black.

MICARTA
The most common form is linen micarta. Similar construction as G-10. The layers of linen cloths are soaked in a phoenolic resin. The end product is a material that is lightweight, strong, as well as having a touch of class (thus dressier than G-10). Micarta has no surface texture, it is extremely smooth to the touch. It is a material that requires hand labor, which translates into a higher priced knife. Micarta is a relatively soft material that can be scratched if not treated properly.

CARBON FIBER
Composed of thin strands of carbon, tightly woven in a weave pattern, that are set in resin. It is a highly futuristic looking material with a definite "ahhhh" factor. Of all the lightweight synthetic handle materials, carbon fiber is perhaps the strongest. The main visual attraction of this material is the ability of the carbon strands to reflect light, making the weave pattern highly visible. Carbon fiber is also a labor-intensive material that results in a rather pricey knife such as case collectible knives.

ZYTEL
Du Pont developed this thermoplastic material. Of all synthetic materials, ZYTEL is the least expensive to produce, which explains the abundance of work or utility knives that have this material. It is unbreakable: resists impact and abrasions. ZYTEL has a slight surface texture, but knife companies using this material will add additional, more aggressive surface texture to augment this slight texture. Sog Specialty Knives is common for using zytel.

TITANIUM
A nonferrous metal alloy, the most common form of titanium is 6AL/4V: 6% aluminum, 4% vanadium, and 90% pure titanium. This is a lightweight metal alloy that offers unsurpassed corrosion resistance of any metal. It has a warm "grip you back" feel and can be finished either by anodizing or bead blasting. Aside from handles, titanium is also used as liner materials for linerlock knives for it is a rather "springy" metal. Titanium is used usually on collectible pocket knives and chef knives.

ALUMINUM
Just like titanium, aluminum is also a nonferrous metal. Commonly used as handles, aluminum gives the knife a solid feel, without the extra weight. The most common form of aluminum is T6-6061, a heat treatable grade. The most common finishing process for aluminum is anodizing.

ANODIZATION
An electrochemical process which adds color to titanium, which is especially conducive to this coloring process. Depending on the voltage used, colors can vary (high voltage = dark color, low voltage = light color).

BEAD BLASTING
A process by which steel, aluminum, and titanium are finished. Bead blasting is commonly found on tactical folding knives and fixed or bowie knife blades, for it provides a 100% subdued, non-glare finish.


Blade Steels

1) AUS-8 (also referred to as 8A) (some text courtesy of Boker Knife Company) - Commonly found in a Kitchen Knife Set, the words "stainless steel" are misleading, because, in fact all steel will stain or show discoloration if left in adverse conditions for a sufficient time. Steel is made "stainless" by adding Chromium and reducing its Carbon content during the smelting process. Some authorities claim that there is a serious performance trade off with stainless steel: As the Chrome increases and the Carbon decreases, the steel becomes more "stainless". But it also becomes more and more difficult to sharpen and, some claim, the edge-holding potential is seriously impaired. We have found that most stainless steel blades are as sharp as other material blades and hold the edge longer. AUS 8A is a high carbon, low chromium stainless steel that has proven, over time, to be a very good compromise between toughness, strength, edge holding and resistance to corrosion.

2) ATS-34 - premium grade of stainless steel used by most custom knife makers and upper echelon factory knives. Also common with the making of quality tactical folding knives or production collectible pocket knives. It is Japanese steel, owned by Hitachi Steels. The American made equivalent of ATS-34 is 154CM, a steel popularized by renowned maker Bob Loveless. Boker pocket knives are usually made of ATS-34.

3) GIN-1 (formerly known as G2) - another low cost steel, but slightly softer than AUS-8.

4) CPM-T440V - currently touted as the "super steel", it outlasts all stainless steels on the market today. It is, however, harder to resharpen (due to its unprecedented edge retention). But the tradeoff is that you do not have to sharpen as frequently. CPM-T440V is widely used by custom knife makers and is slowly finding its way into high-end or gentlemen's folding knives.

5) SAN MAI III - (text courtesy of Boker Knife Company) An expensive, traditional style Japanese laminate. Hard, high carbon stainless forms the core and edge of the blade, while two layers of tough, spring tempered stainless support and strengthen it. The resulting blade possesses the best qualities of both types of steel. This laminate is 25% stronger than the incredibly tough AUS 8A stainless . The telltale sign of genuine San Mai III is a thin line near the edge that runs the entire length of the blade. This line is created in the grinding process as the layers of steel in the blade are exposed. The distance the line is from the edge varies from knife to knife because every piece of San Mai III steel is unique. Like AUS 8A stainless, San Mai III is treated in modern, precise conveyor furnaces and subjected to a sub zero post hardening process. This improves the microstructure of the steel by eliminating retained austenite. The resulting blades are more elastic and have better edge holding characteristics than standard stainless steels.

6) 420J2 - (text courtesy of Boker Knife Company) Due to its low carbon high chromium content this steel is an excellent choice for making tough (bends instead of breaking), shock absorbing knife blades with excel lent resistance to corrosion and moderate edge holding ability. It is an ideal candidate for knife blades that will be subject to a wide variety of environmental conditions including high temperature, humidity, and airborne corrosives such as salt in a marine environment. This extreme resistance to corrosion via its high chrome content also makes it a perfect choice for knife blades which are carried close to the body or in a pocket and blades which will receive little or no care or maintenance.

Carbon V (From Cold Steel) - An exclusive carbon alloy steel, formulated and extensively treated to achieve exceptional properties. Carbon V was developed and refined by using both metallurgical and performance testing. Blades were subjected to the "Cold Steel Challenge" as a practical test, and then they were sectioned, so that their microstructure could be examined. In this way we arrived at the optimum steel AND the optimum heat treatment sequence to bring out the best in the steel. Cold Steel buys large quantities of premium high carbon cutlery steel with small amounts of elemental alloys added in the smelting stage. These elements enhance the blade's performance in edge holding and elasticity. The steel is then rolled to their exact specifications to establish optimum grain refinement and blades are blanked to take full advantage of the grain direction in the steel.

The blanks are heated in molten salt, quenched in premium oil and tempered in controlled ovens. Then they are ground. The new blades are then subjected to expert heat treatment, involving rigidly controlled austenizing temperatures, precisely defined soak times, proper selection of quenching medium and carefully monitored tempering times and temperatures. This heat treatment sequence results in blades which duplicate and often exceed the properties of the most expensive custom forgings.

Premium U.S. High Carbon (from Cold Steel)- Cold Steel's Premium Carbon Steel is used in a variety of our low cost highly functional knives. Chemical content and microstructure from the mill is specified by Cold Steel and each lot is subjected to the same metallurgical examination before being used in production as our world famous Carbon V. The Steel is a very clean,fine grained material with a high carbon content for toughness and response to heat treatment. Cold Steel has designed a special heat treatment for this material which maximizes toughness in combination with more than acceptable edge holding ability, resulting in a blade which will satisfy even the most discriminating user.

S30V - Revolutionary S30V steel blades are harder, more wear resistant and far less brittle than any standard 440C series stainless steel blade. Tests also show 45% better edge retention than 440C stainless.

Titanium - Unlike stainless steel knives, titanium knives are almost completely rustproof and corrosion resistant because they contain no carbon. The result is a knife that will hold an edge for a very long time. Titanium steel knives require almost no sharpening or maintenance.


Blade Shapes

Clip Point – A clip point blade has a concave or straight cut-out at the tip (The "clip"). This brings the blade point lower for extra control and enhances the sharpness of the tip. You will often find a false edge with the clip point. These types of blades also often have an abundant belly for better slicing capabilities.

Dagger/Double Edge - A double edge blade is sharpened on both sides ending with the point aligned with the spine, in the middle of the blade.

Drop Point – The drop-point blade has lowered tip via a convex arc. This lowers the point for extra control and also leaves the strength. This type of blade also has a good-sized belly for better slicing.

Hook Blade – The edge of a hook blade curves in a concave manner.

Santuko – Is a Japanese chef's knife. The spine curves downward to meet the edge and the belly curves slightly.

Scimitar – This is a curved blade with the edge on the convex side.

Sheepsfoot – The spine of this blade curves downward to meet the edge. This leaves virtually no point. This type of blade typically has little or virtually no belly and is used mainly for slicing applications.

Spear Point – The point of this blade is exactly in the center of the blade and both edges are sharpened. The point drops all the way down the center of the blade.

Tanto – The point to this style blade is in line with the spine of the blade. This leaves the point thick and strong. There are quite a few different variations of how tanto blades are designed. The way the front edge meets the bottom edge, whether at an obtuse angle or a curve is one difference. You will also find differences in the point being clipped or not and whether there is a chisel grind.

Trailing Point – The trailing point blade's point is higher than the spine. This is typically engineered with an extended belly for slicing, with the point up and out of the way.

Locking Mechanisms & Types

Axis Lock- The features of the Axis lock are significant and greatly enhance the function of knives. First and foremost is the strength. This lock is definitely more than adequate for the demands of normal knife use. A close second to strength is the inherent Axis advantage of being totally ambidextrous without user compromise. The blade can be readily actuated open or closed with either hand- without ever having to place flesh in the blade path. Lastly, and certainly not any less impressive, is the indescribable "smoothness" with which the mechanism and blade function. By design there are no traditional "friction" parts to the Axis mechanism, making the action the much smoother. And it's all reasonably exposed so you can easily clean away any unwarranted debris. Basically, Axis gets its function from a spring-loaded bar that rides forward and back in a slot machined into both liners. The bar extends to both sides of the knife; spanning the space between the liners and is positioned over the rear of the blade. It engages a ramped notch cut into the tang portion of the knife blade when it is opened. Two omega style springs, one on each liner, give the locking bar its inertia to engage the knife tang, and as a result the tang is wedged solidly between a sizable stop pin and the Axis bar itself. It's a lot of words in an attempt to describe simplicity, but the very best way to truly appreciate the Axis lock is to experience it for yourself firsthand. There are several models to choose from with more on the way.

Balisong
- Also known as Butterfly Knives. The handle to this style knife is in two separate pieces and pinned to the tang. A third pin fixes between both sides to lock the blade into an open position.

Block Lock - This folder lock has a spring loaded block located on the center pin. The block extends into a hole in the tang to lock the blade open.

Clasp - This style folding knife has no lock or backspring.

Lockback - This style of lock has a spring-loaded locking bar with a tooth at the end. The tooth falls into the notch cut into the blade tang and is held there under the spring tension. A cut out in the handle spine houses the release for the lock. These locks generally require 2 hands to unlock and close.

Locking Liner - (a.k.a. linerlocks) This particular locking system was refined by knife maker Michael Walker. The actual locking mechanism is incorporated in the liner of the handle, hence the name. If there is a metal sheet inside the handle material, it is called a liner. With a locking liner, opening the blade will allow this metal to flex over and butt against the base of the blade inside the handle, locking it open. Moving this liner aside will release this lock allowing the blade to close. Disengagement of the lock is performed with the thumb, allowing for one handed, hassle free action. Locking liners are commonly found on tactical folding knives, both production and custom.

Ringlock - This design has been around since the 1890's. The Ringlock is similar to the Slipjoint, but it has a rotating slipring instead of a backspring.

Rolling Lock - This design uses a sort of bearing that rolls into the locked position.

Sebenza Lock - The concept of this lock is comparable to the Liner Lock. A hollowed out section of the scale is fixed into the handle cavity to lock the blade open.

Slipjoint - The slipjoint is one of the more common designs for folding and pocket knives. Instead of a lock, the slipjoint utilizes a backspring to create resistance to hold the blade open.

Swinglock - There is one pivot pin and one locking pin used to design this style lock.

Wood Lock - This lock was designed by Barry Wood. The handles and blade are attached to a central pin and pivot independently. A second pin is fixed into the inside of one scale and extends into slot in the tang to lock the blade open.

Blade Grinds

Hollow Grind
The most common grind, found on the majority of custom and production pieces. Hollow ground blades have a thin edge that continues upwards, and is the grind is produced on both sides of the blade. Since the cutting edge is relatively thin, there is very little drag when cutting. Examples of knives with hollow ground blades: Spyderco Howard Viele C42 and Kershaw Ti-ATS-34.

Flat Grind
Flat grinds are characterized by the tapering of the blade from the spine down to the cutting edge. This style of grind is also referred to as a "V" grind, since the cross section of this grind resembles that letter. The chisel grind, a popular style for tactical blades, is a variation of the flat grind. On a chisel round blade, it is ground on one side, and on the other it is not. These blades are easier to sharpen, because you sharpen one side only. Example of a knife with a chisel ground blade would be the Benchmade 970 Ernest Emerson CQC7. Examples of knives with a flat grind are the Benchmade Mel Pardue 850 and Spyderco's C36 Military model.

Concave Grind
Similar to the flat grind in that the blade tapers from the spine to the cutting edge, except the taper lines are arcs instead of straight lines.

Convex Grind
Similar to the flat grind in that the blade tapers from the spine to the cutting edge, except the taper lines are arcs extending outward instead of inward as in the concave grind above or straight lines. If you picture a pumpkin seed, you will get a good idea of what the cross sectional view of this grind is like. Noted custom knife maker Bill Moran is credited for bringing the convex grind into the focus of knife making.

Chisel
The chisel grind is ground on only one side of the blade. It's easy to produce and easy to sharpen. It is often ground at around 30 degrees which contributes to a thin and sharp edge.

Sabre
The sabre grind has flat edge bevels that typically begin about the middle part of the blade and runs flatly to the edge. The edge is often left thick and thickens quickly past the edge. This is a great grind for chopping and other hard uses.

Scandinavian Single-Bevel
the Scandinavian single-bevel grind looks similar to a sabre grind. The difference between the two grinds is that the Scandinavian single-bevel grind has no secondary edge bevels. This grind has an extremely thin and incredibly sharp edge.




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