I. Knife Selection
Stainless steel resists corrosion and holds an edge better than high carbon steel. Although the name would imply otherwise, it will stain or discolor if left in adverse conditions long enough. The process of making stainless steel involves adding Chromium and reducing its Carbon content during the smelting process. 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 authorities claim, the edge-holding potential is seriously impaired. We find that most stainless steel blades are as sharp as other material blades and hold an edge just as well as high carbon blades.
Most unserrated blades are designed to slice soft things like animal flesh, tape, food products or string, but would wear down quickly if used on hard or rough textured objects (like rope or webbing). For the latter objects, a partially serrated blade is a better choice.
A quality blade may need sharpening only every 2 to 3 years. We suggest knives be professionally sharpened but if you do it yourself, use an India stone not a diamond hone. The diamond bone grinds too much of the edge down. Be sure to choose the grind style best suited for the tasks performed with the knife.
For car camping or emergency home lighting, various models of lanterns are widely available and work best.
Handles, locks and grips: Be sure the handle is comfortable for you, the locking mechanism is strong and the grip is textured or rubber. For fixed-blade knives, make sure the blade extends well into the handle for improved strength and balance.
II. Blade Steels
AUS-8 (8A) - 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.
ATS-34 - Premium grade of stainless steel used by most custom knifemakers and upper echelon factory 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.
GIN-1 - Another low cost steel, but slightly softer than AUS-8. Formerly known as G2.
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 factory knives.
SAN MAI III - 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.
420J2 - 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 excellent 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.
440C - A high-chromium stainless steel with great corrosion resistant properties. It is slightly softer than the 154CM. It is considered by many to be one of the finest blade materials available domestically. It takes and holds a keen edge with a minimal amount of effort and maintenance. Characteristics of this steel include extremely high corrosion resistance when compared to ATS-34 and some other "stainless steels," high wear resistance, and good cutting qualities. This fine stainless steel has lost some its "limelight" due to the popularity of ATS-34 in the past few years, but for wet or damp environments 440C is a superior choice.
0-1 - Is perhaps the most forgiving of any knife quality steel other than the very simple alloy types, and produces a blade of excellent quality for most normal use. It can be heat treated very easily. Edge holding is exceptional.
D-2 - Is another air hardening tool steel, but with 12% chrome and excellent, if not superb, wear resistance. A high carbon content steel for great abrasion resistance. The resistance also holds true in both sawing and grinding, even while the steel is fully annealed. D-2 anneals at somewhat higher temperature than A-2 and will not take a true, mirror polish. Definitely a steel for the advanced craftsman. Its major drawback is the orange peel appearance of the surface when finished to a high gloss. It is just below the stainless threshold so coating with BT2 adds corrosion resistance.
154CM - The American made equivalent of ATS-34. USA made by Crucible Steel. Developed for use in military jet engine turbine blades during the war. Due to its high carbon/chromium content it offers exceptional wear and resistance. For blade use, it offers super-fine grain structure which bodes well for excellent lasting edge sharpness.
BG-42 - The correct name for this steel is Lescalloy BG42 VIM-VAR. This is a high performance bearing steel made by Latrobe Steel Company in Latrobe, PA. A special manufacturing process combined with a very specific alloy results in a clean steel with good resistance to wear and corrosion. This type of steel is used for domestic, international and military aerospace applications. When compared with other types of steel, BG42 demonstrates superiority in areas of hardness, hot hardness, retention of hardness, corrosion resistance, oxidation resistance and wear resistance. The introduction of 1.2% Vanadium increases the steels toughness and edge retention.
Talonite - Talonite is a Cobalt Chromium alloy, a member of the Haynes Alloy family, that has been treated with a new hot rolling age hardening process. Talonite is the same composition as alloy 6BH (Stellite), except for the hot rolling and age hardening. The direct age hardening after hot rolling provides maximum hardness and wear resistance. The advantages this creates are increased wear resistance, increased hardness, and improved machining characteristics. Talonite is much easier to grind than other Stellite type alloys and has improved edge retention qualities.
CPM - A family of alloys with unique or enhanced properties that cannot be made by conventional steel manufacturing methods. In almost any application, CPM grades offer improved wear-resistance, toughness and grindability. CPM steels have no alloy segregation and exhibit extremely uniform carbide distribution. The types of vanadium CPMs found in many recent generations of knife blade steels include: 3V, 9V, 420V and 440V. Considered more "stiff" than ATS-34 or 154CM, but with longer edge holding properties and resistance to rust and staining.
A2 - A popular grade of cold work die tool steel. It has better wear resistance and toughness than O1 plus the dimensional stability offered by air hardening qualities. it's properties are more advantageous to certain types of knife making. More prone to rust and staining compared to "stainless steels".
S30V - A stainless steel created with the knife market in mind, alloyed to accommodate specific capabilities and manufactured to ensure clean, uniform steel. Unlike traditionally cast and rolled steels, S30V is made using the powder metallurgy process, a process that reduces molten alloy components to minute balls or powder which results in every grain comprising the exact composition of alloy elements. The powder is compressed under significant force to a homogenous, solid state and the steel is rolled to required stock size. Molecules are uniform, inclusions of impurities are insignificant and the development of large chrome carbides is a thing of the past.
M2 High-Speed Steel - A very tough, tool grade steel used as cutting steel and offering high abrasion/wear resistance. Offers high-impact strength with incredible edge holding properties. Non-stainless by nature, but Benchmade heat-treats before applying the BT2 coating to provide a high level of corrosion resistance.
III. Blade Types
A normal blade (a.k.a. single-edge) has a curved edge and flat back. The flat back lets one use fingers to concentrate force, which makes the knife heavier and stronger for its size. The curve concentrates force, making cutting easier. Therefore, it can chop as well as pick and slice. The single-edge is less expensive to produce than a double-edge.
Dagger / Spey
A spey blade (a.k.a. dagger or double-edge) has two curved edges. This type of blade slices in either direction and has a strong sharp point. This is the strongest traditional style of knife and makes an excellent weapon because of its two-sided cutting ability and strength. Many believe that the best all-around blade is an asymmetric spey, or dropped-spey which has the larger curve on the lower side.
A trailing-point blade (sometimes simply called a curved blade) has a back edge that curves upward. This allows a larger cutting edge for a lightweight knife, and also better slicing than a normal knife.
A clip blade is like a normal blade with a clip off the tip to make the tip thinner and sharper. The back edge of the clip may have a second sharpened edge, called a cut swedge. The sharp tip makes the blade exceptional as a pick, or for cutting in tight places. If the clip is sharpened, this working knife may double as a fighting knife. This is an extremely popular blade although not a strong as a spey. The Bowie design offers a clipped blade that's good for fighting, with the strength of a spey.
A sheepsfoot blade has a straight edge, and a curved dull back. It allows the most control because the back, dull edge is made to be held by fingers. It's good for whittling, and as the name implies - cleaning sheep's hooves.
A tanto blade has a straight back, a straight edge, and is more angular in design. The predominant feature is the tip which is actually a second edge, almost chisel-like, sweeping back from the point at a 60-80 degree angle.
A hook blade has one sharpened edge that curves in a concave manner. Often used for skinning and rescue knives.
IV. Blade Grinds
The type of grind used in chisels. Where one side of the blade is totally flat, and only one side is ground at an "angle" or "bevel". Commonly found with "tanto" style blades, the chisel grind found popularity for tactical use. The philosophy being chisel ground blades were less difficult to sharpen on the field and were of a great thickness and there fore stronger.
Also called a hollow grind, it is 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. The most common grind, found on the majority of custom and production pieces. Hollow ground blades have a thin edge that continues upwards, and the grind is produced on both sides of the blade. Since the cutting edge is relatively thin, there is very little drag when cutting. Advantages: the hollow grind can be made incredibly thin, in fact, the sharpest of the blade cross-sectional areas shown. As the blade is sharpened repeatedly, the blade will remain thin well into a third or more of it's grind, sometimes half, without needing reground, only sharpened. Disadvantages: blade behind the cutting edge is thin, not much metal to support chopping or abuse, must be constructed with finer tool steels to support thin edge with toughness at high hardness. Special equipment and lots of skill required to grind and polish correctly.
Also called a taper grind or convex wedge, it is 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 convex 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. Advantages: used on a knife, a thin cutting edge, stout cross sectional area good for chopping, tough profile with plenty of meat (steel) to support the edge. This is the only grind suitable for a very thin blade (less than .0625"). Disadvantages: sharpening the blade in continuous use renders a thick cross-sectional area, requiring relieving. On a thin blade, this is okay, because in sharpening, the taper is ground away. Not a very attractive grind, it looks washed over. Many makers and manufacturers use this grind because it's one of the easiest grinds to construct. Any slack belt grinder or flat platen can make a decent taper grind.
Also called a compound bevel, it has a back bevel on the blade behind the edge bevel (the bevel which is the foremost cutting surface). The back bevel keeps the section of blade behind the edge more acute which improves cutting ability over the less acute edge. In practice, double bevels are common in a variety of edge angles and back bevel angles, and Western kitchen knives generally have a double bevel, with an edge angle of 2022 (included angle of 4044). Advantages: This grind is much less prone to chipping or rolling than a single bevel blade. Disadvantages: being less acute at the edge than a single bevel, sharpness is sacrificed for resilience.
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. Advantages: easy to grind using minimal equipment, thin cutting edge, plenty of support for cutting. Disadvantages: as the blade is sharpened, the cross-sectional area quickly becomes thick, necessitating regrinding or relieving of the cutting edge.
Similar to a flat grind blade except that the bevel starts at about the middle of the blade, not the spine. Also named "Scandinavian Grind", it produces a more lasting edge at the expense of some cutting ability and is typical of kitchen knives. Also sometimes referred to as a "V Grind", made with strength in mind and found on tactical and military knives.
V. Coatings & Treatments
BC1 Coating (Boron Carbide) - An extremely hard, thin ceramic coating applied in a vacuum chamber. Its extreme hardness and excellent adhesion provide wear resistance and lubricity while creating an attractive visual distinction in the process.
BT2 Coating - A Benchmade proprietary blade coating which is a black Teflon based polymer offering corrosion protection which exceeds the ASTM-117 specification for saltwater corrosion resistance. Due to its high lubricity, it helps make the knives operate more smoothly.
Heat-Treat - Heat-treating steels changes the structure of the material to make it stronger or weaker depending on the process used.
VI. Handle Materials
A modern age material made of alternating woven layers of carbon strands and epoxy which provides exceptional strength to weight ratios.
Select hardwood veneers are vacuum impregnated with special dyes and resins. Sheets are then layered and pressured under tremendous heat and pressure. This process creates a fashionable, stabilized real wood medium for a durable and attractive composite.
6061 T-6 Aluminum
Originally developed as a premium aircraft grade aluminum which is aged to a T-6 temper for improved toughness. Precisely machined to spec, bead blasted for texture and then anodized with hard oxide coating for enhanced grip and wear ability.
Developed as a circuit board material capable of withstanding extreme conditions without distortion or negative effect. Impervious to moisture or liquid for ideal outdoor toughness. A highly compressed epoxy and woven glass composite providing nearly indestructible strength and is of nominal weight.
A modern engineered plastic offering high-strength, minimal flex and optimally light weight properties. Benchmades 30% glass fill mix provides great all around qualities.
A lightweight glass filled nylon, engineered for strength and durability while still offering moldable versatility. Its widely used in the automotive industry in engine related components. For knife-crafting purposes, molded handles offer lightweight, durable performance at an inherently economical value.
VII. Liner Materials
6AL-4V Titanium - A slightly lighter weight, modern metal offering incredible strength and resiliency. Key properties include non-magnetic and corrosion resistance.
410 Stainless Steel - An ideal 400 series steel offering good corrosion resistance and workability.
IIX. Locking Mechanisms
The locking system works by using a sliding metal pin that is pushed into a notch in the blade, using springs to hold it in place. The shear strength of the metal pin is what holds the knife open, and as such, is significantly stronger than the now standard locking liner design. This design allows for ambidextrous one handed opening and closing, and the lock actually assists the blade in opening.
A locking system where the blade is held open and locked in place by a plunge shaft. The lock is engaged and disengaged by a "button" at one end of this shaft exposed on the handle side. This type of lock is considered exceptionally strong if engineered correctly. Due to more complex nature of this type of lock it is not as common as the liner type locking systems.
A locking system derived from the "liner lock" where the leaf or "liner" is actually part of the handle. Commonly found in folders where no scales are used and the handles are solid slabs of titanium.
A "tried and trued" blade locking system where the "back" of a folding knife pivots or seesaws to lock a blade open. A pair of nesting notches in the back spacer and blade facilitates the locking action. The lock back is released by pressing down and pivoting the back spacer notch up and above the blade. While considered more secure than a liner lock, the process of unlocking often requires both hands.
This particular locking system was refined by knifemaker 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 will 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 folders, both production and custom.
IX. Knife Action
A folding knife is one that is hinged and has any of the above locking mechanisms. They usually open out the side (OTS). You can deploy just about any folding knife by "popping" it open, which can be much faster than a switchblade. From a legal standpoint, you have a degree of plausible deniability with respect to its purpose as a weapon.
Gravity knives, also called kinetic knives or paratrooper knives, are any knife which has a blade which is released from the handle by the force of gravity or the application of centrifugal force. They can either open out the front (OTF) or (OTS). Kinetic opening is as fast as a switchblade, if not faster, because no button is required to open the knife.
Balisong / Butterfly
A blade enclosed by its handle, which is designed to split down the middle, without the operation of a spring or other mechanical means, to reveal the blade. Balisong is the Tagalog name of the famous Filipino "butterfly knife." This word is less ambiguous than "butterfly knife" which is also the name of Wing Chun Kung Fu short swords. Balisong means "broken horn" and refers to the mobile handle which protect the blade when closed. The balisong was the first knife which could be opened with one hand, very quickly.
Any knife which has a blade which opens automatically by hand pressure applied to a button, spring or other device in or attached to the handle of the knife. These are often times called a Switchblade or a Stiletto. They can either open OTF or OTS. An auto knife can only be opened quickly if the knife is already in hand with the thumb or a finger already on the firing button. Finding the button can be difficult if someone is your getting attacked, or if you're shaking from an adrenaline rush. Automatics often have a safety built in to prevent the knife from opening in your pocket, which is just one more button to fumble with. A quality automatic is often much more expensive than a folding knife. They are illegal to carry in almost every state/country.
X. Serration Information
Serrations on field knives are usually made up of two different sized scallops, two distinct patterns, and two distinct edge styles. Read on
A typical serration pattern alternates two minor (smaller) points and one major (larger) point. There are, however; serration designs where the concave scallops are even as those in bread knives or household steak knives.
A standard serration is one in which the major width of the minor scallop is concave (an "innie"). This serration style is found on the Gerber Gator Serrater, the Beretta AirLight Serrated, and Spyderco knives. A reverse serration is one in which the major width of the minor scallop is convex (an "outie"). This serration style is found on the Mission Knives MPK and most Benchmade knives.
Some believe that reverse serrations tend to work better when cutting wet line and materials filled with "gunk." The theory is that reverse serrations tend to be self-cleaning, in that the convex part of the scallop tends to push away the "gunk" that would normally clog the concave scallop.
The two style of serrated edge are radius and pointed: radius being a smoother, curved serration and pointed being exactly as it sounds pointed. We feel that radius edge serrations tend to cut easier than pointed serrations, but do not initially penetrate as easily. While a radius edge will glide through the material, a pointed edge will snag or dig into material being cut. This can be seen when cutting braided or woven materials such as nylon line, webbing, rope, or cord. A pointed edge serration will work best, however; when maximum penetration is required.
Miscellaneous Serration Info
Chisel serrations are now featured by a number of manufacturers. These serrations may be ground onto the blade with a small rotary tool, a chop saw/cut off saw wheel, or a chain saw file. The blade is usually sharpened first before the serrations are put on. This technique results in a sharpened blade edge between concave scallops. The benefit behind this design is two-fold: (a) the process can easily be done by a custom knife maker, and (b) the finished knife edge tends to "bounce" on the material being cut, thereby increasing the amount of applied force.
Laser serrations are another new technology often cleverly marketed as being the most revolutionary knife making technology in the world. Manufacturers claim these serrations keep their edge longer, or in some cases forever. While they would seem to hold their edge longer, it is only the "sawing" that allows the blade to remain functional even when it is quite dull. This in turn creates the illusion that the blade keeps its edge longer. In addition, the serrations effectively lengthen the total cutting edge which means for any given use, it will stay sharp longer - all other things being equal. The simple fact, however; is that all blades will dull eventually and the biggest problem with the laser serrated blade is that once dulled, it is impossible to sharpen. The only actions you can take when your laser blade gets dull is 1) grind the serrations off completely for a straight knife edge, or 2) return it to the company for a new one, depending on the manufacturers policy.
A Subjective Opinion on Serrated vs. Flat Blades
Serrated blades have their uses and strong points, but not as a primary wilderness blade, in my opinion. Stick to a plain edge for general use. Serrated blades do not lend themselves to many of the carving and chopping chores a knife may be used for. Their forte is slicing, or sawing or tearing, as the case may be. They are particularly good at slicing nylon and similar slick synthetic line, rope and webbed belts and harnesses, as well as clothes and flesh. In other words, they are great for paramedic or law enforcement use or as a defensive blade. They are an acceptable choice for marine survival use which is less demanding of a knife edge and where cutting lines and slicing open fish are the primary uses.
In the field, a person will cut whatever is needed, on any surface available. These "cutting boards" could be anything from the lid of a steel tool box, to the side of a pick-up truck bumper, or even a rock. The straight edge blade will soon become damaged under these harsh conditions, whereas, the serrated edge, with its protected inner edges, can sustain terrible damage and still cut.
A big down-side, however; is that serrated blades are much more difficult to sharpen in the field, though the right sharpener (round or tapered round, depending upon serration style) and practice will solve this problem. If you're caught out in the field without a knife sharpener, then you are out of luck. You can do a respectable job sharpening a plain edge blade using natural stone. You'll not have much success trying to do that with a serrated blade.
If you just cannot live without a serrated edge, look for a blade with something like a 70/30 or 60/40 split between the plain and serrated edge, with the plain edge forward of the serrated. Or, better yet, carry a separate serrated edge knife, or a knife with a separate serrated blade.
XI. The Truth Behind "Blood Grooves"
History of the K-bar
Owners of the USMC 1219C2, or k-bar, are probably aware of the term blood groove and are also probably under the impression that these serve some sort of purpose. We at Delta Gear take pride in dispelling the myths often created by clever marketing teams and therefore would like to give you a little history on the USMC 1219C2, the grooves-in-question (otherwise known as fullers) and how the term blood groove came into existence.
The first 1919C2 was created in the style of a commercial hunting knife that was produced by the Union Cutlery Company. And the Union Cutlery Company took their idea from a wildly successful Ideal hunting knife made by the Marbles Company. The Marbles knife had fullers that were quite wide and deep and were positioned lower on the blade. This ingenious design allowed the Marbles knife to be successfully flat-sharpened (by holding the blade flat) on a flat stone while in the field.
On comparing the Marbles knife to the USMC 1919C2 (or the Union Cutlery knife for that matter), one will immediately notice that the fullers on the latter two knives are much narrower, not as deep, and placed higher on the blade than those on the Marbles knife. These differences unfortunately negate the true purpose of the design and are rendered useless in terms of sharpening advantages. While the fullers on the Marbles served a valuable purpose in the field, it was completely lost to the designers who copied it.
Once realized, the knock-off designers needed a justification for their blundered design which is how the suction theory and the term blood grooves came to be. In theory, these blood grooves help release the suction when withdrawing the knife from an animal or person. In this scenario, it is presumed that the victims muscles contract around the knife blade, creating a vacuum which makes the knife difficult to withdraw. Supposedly on a knife with a blood groove, blood can run through the grooves and break the suction, allowing the knife to be withdrawn more easily. One problem is that there is no proof that the muscles actually contract around a knife blade; and the second problem is that people testing knives with and without blood grooves say there is no noticeable difference. Experts agree that if your knife cuts its way in, it can cut its way out with or without blood grooves.
Now, taking that all into consideration lets just return to the original term fuller from this point forward. Its true that a fuller can serve a very important structural function, depending on the size of the blade. In swords, this design plays a far greater importance in terms of weight reduction. In a knife, however; the decreased weight is so small, it can be deemed insignificant. The strengthening properties of a fullered sword blade are also lost in knife design. Many believe the fuller plays a strictly decorative role on knives or swords under two feet long.
The bottom line is the term blood groove may sound cool but in fact is just a clever marketing scheme. Sorry folks, but thats the story and were sticking to it.