Knife Buyer's Guide

We believe that a knife and tool are essential to modern day life. Man’s oldest tool was a knife and everyday there are still a myriad of chores that require its use. When purchasing a knife, the first question you may ask yourself is “what kind of knife do I need?” We always say that the best knife is the one that you have or will carry. If it is an everyday knife carried in a pocket, size and comfort are important. If it is a knife that will be used in the field, a sheath knife will be appropriate. Another major determining factor is how the knife will be used. The rule of thumb is that a fixed blade is stronger and easier to use if you will carry it or have it accessible. After all, you don’t normally see folding kitchen knives! Modern folding knives can be used for almost anything today including, hunting, outdoors, general carry, etc. Choose a knife that fits your hand, your personality, and your pocket book…in that order. More and more users today are carrying our combination tools that not only have a knife blade, but many other tools as well. Like shoes, there is no one knife that will fit all your needs. We find that many of our customers carry multiple knives/tools for just that reason. What ever you decide use your knife responsibly and carefully.

General Information

• Glossary of Knife Components
• Types of Blade Steel
• Proprties of Various Steel Types
• Types of Handle Materials
• Types of Blade Shape
• Types of Edge Styles
• Types of Blade Finish and Coating
• Considerations with Blade Size

Fixed & Folding Knife Information

• Folding Knife Opening Mechanisms
• Folding Knife Locking Mechanisms
• Blade Opening Features for Folding Knives
• Additional Features on Fixed Blade Knives
• Cryogenic Heat Treatment in Blades
• Types of Fixed Blade Sheaths

Multi-Tool Information

• General Multi-Tool Information
• Replacing Components in Multi-Tools
• Information on Compound Leverage in Multi-Tools
• Types of Pouches available for Multi-Tools and Folding Knives
• Thoughts on Multi-Tool Finishes
• Considerations with Multi-Tool Opening Mechanisms
• Thoughts on Multi-Tool Weight

Glossary of Terms:

A. Edge
The sharpened part of the blade, from point to bolster (E to F). The edge can be either straight, serrated, or a combination of the two.


B. Spine

The side opposite the sharpened edge is referred to as the spine.


C. Handle

The handle envelops the tang (H) and is usually fastened by rivets or encased in plastic or metal.


D. Tip

The third of a blade's tapered end, opposite the handle.


E. Point

Located at the tip of the knife, the point should be sharp and relatively thin. It is used for making incisions, cutting, and carving.


F. Bolster/Guard

A thick piece of metal between the handle and the blade that is typically found on fixed blade knives. It is made to add weight to the knife, provide it with better balance, and create a comfortable resting place in the hand.


G. Butt or Pommel

The butt or pommel end of a knife is located opposite from the tip at the end of the handle.


H. Tang (not pictured)

The part of the blade that runs from the bolster back into the handle is known as the tang. There are two types of tangs. A full tang runs the entire length of the handle while a half tang only runs a partial extent of the handle. Higher end knives generally have a full tang.

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Blade Steel

There is a saying that the heart of a knife is its steel. Although steel is very important, it is not the only factor in determining the performance of a knife. Other considerations are heat treatment and blade shape/profile. There are various levels of quality in knife steel. Most modern knives are made using stainless steel.

Stainless steel is a steel alloy with a minimum of 11% chromium content by mass. By varying the amount of chromium and carbon in the makeup of the steel different properties can be achieved.

Below is some basic information on the grades and characteristics of different steels:

Good

These entry-level stainless steels are typically made in Asia. They have an adequate edge holding ability, are rust resistant, and offer good value. These steels tend to be softer compared to higher grade steels and require more frequent sharpening to maintain the best performance.

Examples:

• 420
• 440A
• 7Cr13MoV

Better

Better grade stainless steels are more expensive and have higher chromium content. They offer greater edge holding ability and require less maintenance than entry level grades of steel. Sharpening is relatively easy and can be performed using appropriate techniques. These steels offer a great combination of value and performance making them perfect for everyday use.

Examples:

• AUS6
• AUS8
• 440C
• 8Cr13MoV

Best

The best stainless steel is typically made in the USA and Japan. They tend to come with a cost premium and high chromium content. Additional elements, such as vanadium, are often added to provide superior edge sharpness and retention, as well as enhanced rust resistance. These steels require sharpening less frequently making them ideal for more demanding uses.

Examples:

• CPM 154
• S30V
• VG-10

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Examples of the properties of various steels:

AUS-8 and AUS-6 are Japanese high-grade chromium steels that are a good compromise between toughness and strength, edge holding ability, resistance to corrosion and cost. Typical Rockwell hardness is 56-58.

440A and 440C are high-grade cutlery steels that are very similar to AUS series above. Due to its toughness and relatively low cost, many knives are made of 440 stainless. 440A contains the least amount of carbon and is the more stain-resistant; 440C contains the most carbon and is typically harder.

VG-10 is well-known high-end Japanese steel and is considered premium. It contains vanadium which is known for its toughness. The steel is specially designed for high-quality blades used in cutlery. VG-10 can be sharpened to a fine edge that is very durable. It can maintain a hardness of Rc 60 without becoming brittle.

CPM S30V is a powder-made stainless steel that was developed by Crucible Materials Corporation for its wear and corrosion resistance. Its chemistry promotes the formation and even distribution of vanadium carbides, which are harder and more effective at cutting than chromium carbides. In addition, vanadium carbides give the steel a very refined grain, which further contributes to the sharpness and toughness of its edge. It is considered to be one of the superior steels.

154CM is an American made premium grade stainless steel originally developed for tough industrial applications. It combines three principal elements: carbon, chromium, and molybdenum. Known for its best all-around qualities, it offers great corrosion resistance with good toughness and edge quality. Typical Rockwell hardness is 57-59.

D2 is a high-performance tool steel alloy commonly used in knives and tools. It is not considered stainless steel, as its chromium content is 1 percent less than the classification.

8Cr13MoV is a Chinese stainless steel with a high performance-to-cost ratio, often compared to AUS-8. Tempered around the Rc56 to Rc58 range.

san mai means layered steel. It contains a very hard core steel that is encased in softer more resilient outer layers, Its advantages are in having a blade with an extremely hard edge but that can be flexible as well. There are many combinations of steel used in san mai.

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Handle Materials

Glass Reinforced Nylon (GRN) is a high strength, abrasion and impact resistant thermoplastic polyamide formulation of the family more commonly known as nylon, often with varying degrees of fiberglass, from 13% to 60%, added for additional stiffness. GRN also offers chemical resistance to common chemicals such as motor oil, transmission fluid, and methanol. GRN allows little thermal expansion.

Aluminum comes in many grades. It has good mechanical properties and is one of the most common alloys for general-purpose use. It is typically anodized to offer extra protection and color. Hard anodized coatings are much more scratch resistant.

G-10 is a very durable reinforced material. It is made up of fiberglass soaked in resin, then highly compressed and baked This makes it impervious to liquid and physically stable under extreme changes in temperature. It is most commonly black but is available in various colors. It typically has a non slip finish.

Carbon Fiber is a modern composite made from thin layers of carbon strands that are tightly woven and then cured under high pressure in resin. This makes for a very strong and lightweight material.

Micarta is created from soaking layers of linen cloth in resin and then pressing them together, much like G10. It is available in various colors and can be worked to a very smooth finish.

Kraton is a synthetic replacement to rubber. It offers many of the same properties of natural rubber such as flexibility, high traction, and sealing abilities, but with increased resistance to heat, weathering, and chemicals. Typically, it is over-molded on the knife handle to provide added grip. It comes in a variety of hardness.

Natural Materials include bone, wood, leather and more. They offer a more traditional look to the knives. These are typically applied directly on to the liners of the knife.

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Blade Shape

Drop Point is a pattern used on many knives and is commonly seen on hunting blades. The tip is lowered (dropped) via a convex arc from the spine. This allows the tip to be ground thicker. This convex shape differentiates it from the clip point.

Clip Point is a great all-around format and one of the most popular. It is used on most bowie knives. The blade shape uses a concave or straight cut-out towards the tip.

Sheepsfoot blades really can't be said to have a point. The spine curves down to meet with the straight edge. They can be used safely as a rescue knife or in situations that don’t require a point.

Spear Point is a symmetrical grind with the tip being in the center of the blade. Double edged, the spear point shape makes a great dagger.

Dagger is the format that is designed to maximize piercing. The dagger usually has two sharp edges to reduce the profile and let the knife cut on both sides. It is also symmetrical but can vary to a finer edge than the spear point.

Tanto has become identifiable with a shape that is angular, using two straight edges that are joined. The tip on this format is very strong due to the spine keeping its full width until it nears the tip. The tip then tapers to create the point.

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Edge Type

Straight Edge blades are the standard for general knives and cutlery. They provide an edge that will cut cleanly and be sharpened easily. The choice for hunting, the edge can be repeatedly sharpened quickly.

Fully Serrated blades out perform straight edges when cutting fibrous material like rope. The difference can be remarkable. It is an aggressive edge and often leaves a ragged cut. Serrations typically will stay sharp longer that a straight edge but once dull, are much more difficult to sharpen. There are many systems today that make it easier for sharpening serrations but at some point, the edges will need to be completely refurbished.

Partially Serrated blades offer the advantages of both straight and serrated edges in one knife blade. A partially serrated edge is a good compromise when the blade will be used for general purposes.

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Blade Finish Type

TiNi is short for Titanium Nitride. It is the best coating that can be applied to steel. It is commonly used for black finishes and to increase durability. This finish is known to be both extremely scratch and peel resistant. TiNi is applied to steel through a unique process of plasma deposition performed in a complete air-sealed vacuum.

Satin Finish is a semi shiny finish with a luster falling between bead blasted (matte) and mirror polish (high gloss). It shows fine buffing lines. Satin finish is the most popular finish on production knife blades. Two directional finishes show the bevels of a blade better and requires great hand skill to accomplish.

Mirror Polish is a highly reflective finish typically seen only on high-end, custom, and handmade knives. Besides being incredibly striking visually, mirror polished finishes also aid in corrosion resistance due to their smooth surface. Some lower end knives use a tumbled finish to approximate a high end mirror polish.

Bead Blasting is a non-reflective finish created by blasting the surface of the blade with various media, usually beads or sand. This produces a rougher surface that is more prone to surface corrosion.

Black Oxide, or blackening, is a conversion coating for ferrous materials. It is used to add mild corrosion resistance and for an appealing black appearance.

Black Paint or powder coating is the lowest quality blade coating. The paint gives the blade low reflectivity but has a high probability of chipping and scratching.

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Blade Size

Though usually a matter of personal preference, blade size should be determined by the job for which it is intended and the way in which you will carry your knife.: Typically larger blades are used for outdoors and other heavy-duty applications while smaller blades are appropriate for everyday tasks. Note: before purchasing a knife it is a good practice to check the laws in your state or country regarding legal blade sizes or lengths.

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Folding Blade Opening Mechanisms

Folding knives have a variety of opening mechanisms including spring-assisted, fully automatic and manual.. Note that not all opening mechanisms are legal in all states. Consult your local knife laws for more details.

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Folding Knife Locking Mechanisms

Liner locks use a leaf spring built into the liner to lock the blades. It is a simple lock that is probably the most common. If not built correctly, linerlocks suffer from excessive blade play and failure over time. They can also only be released from one side and therefore are not ambidextrous.

The Piston lock or bolt action lock uses a movable bar that is wedged between the blade tang and the knife handle to lock the blade. When the piston is pulled back against the spring tension, the tang is released. They are very strong and easy to use.

The Cam lock or arc lock uses a pivotal block to lock the blade in place. It can be ambidextrous, is extremely strong, safe, and easy to use. It is considered to be one of the finest locks available.

Lockback is one of the oldest locks in use today. It still can be a great mechanism that locks up very securely. A lever on the back edge of the handle catchs in the tang of the blade and locks it. To unlock, one presses on the back of the lever. It is ambidextrous and safe to operate.

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Folding Knife Blade Features

A Thumbstud is used in many folding knives to open the blade with one hand. Many times they are mounted on both sides of the blade for right and left-handers.

A Thumbhole can be used in place of the thumbstud to allow for easy one-handed opening.

A Nail Nick is a notch carved out of the blade used to open the knife. It is the original system for opening folders. Today it is not as popular or easy to use as a thumbstud.

The Kick or Flipper is an extended tang which passes through the handle of the knife when closed. When pressed, this feature “kicks” the blade open.

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Fixed Blade Features

Rasping or thumb groves are a series of small teeth sometimes found on the spine of a fixed blade. These teeth give greater purchase for a thumb, provide better control and greater down pressure when cutting.

Double Tooth Saws are saws with different sized teeth. They are designed to cut a variety of material well and to clear the saw kerf of cut matrial.

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Heat Treatment

There is more to knife performance than the steel or blade profile. Perhaps the most important component is the heat treatment of the steel. A good solid heat treatment on a lesser steel will often result in a blade that outperforms a higher grade steel with inferior heat treatment. Generally the harder the blade, as long as there is no embrittlement, the more abrasion resistant the steel and the longer the edge will hold. SOG has spent years perfecting the process and has even gone so far as to develop our Cryogenic Heat Treatment to provide superior edges.


SOG's unique Cryogenic Heat Treatment process increases the toughness and wear resistance of our blades. The process involves taking the knife slowly down in temperature to less than -300°F and then back to room temperature. This stress relieves the material on an atomic level and increases overall strength as well as edge retention. Knife edges stay sharper longer with significantly less micro-fracturing and edge-chipping. It’s this dedication to making your knife “SOG sharp” that helps to set us apart from the rest.

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Sheath Information

Kydex sheaths are made from a rigid tough material and offer superb protection for fixed blade knives. These sheaths are excellent for diving applications and tactical use. Certain models offer a grooved exposure point for cutting cord or belt without exposing the entire knife blade. (The groove is a proprietary feature found only on select SOG products)

Nylon, like Kydex, is an excellent choice for tactical applications as most offer the versatility of MOLLE compatibility (military mounting). Many of our nylon sheaths use velcroe retention and safety straps. Nylon tends to be more comfortable to carry than Kydex.

Leather sheaths are a classic choice in fixed blade carrying options. Very versatile and sturdy, leather once broken in makes for almost a custom fit. There is nothing like the patina of well taken care of aged leather.

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Multipurpose Tools

A multi-tool or combination tool is a compact, portable hand tool that combines several individual tool functions in a single item. Because of their compact size they can be carried in a pocket or a belt pouch.

Components may include items like a nail file, tweezers, folding scissors, toothpick, magnifying glass, screwdriver bits, and others. Almost all multi-tools will always have at least one knife blade. There are also versions that have special tools for specific sports or outdoor activities such as golf, horseback riding, hunting, or fishing.

Replaceable Components

Some multi-tools allow users to replace broken components themselves. However, many of the more popular brands require the tool be returned to the manufacturer to have any broken components replaced. Having the ability for you to replace worn out or broken components is an advantage that SOG tools have.

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Compound Leverage

Compound leverage is a patented feature of SOG combination-tools. It provides twice the cutting and gripping force of conventional designs and allows you to squeeze harder with less effort. It accomplishes this with our unique gear drive.

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Carry Pouch

Typically the larger multi-tools will include a pouch that can be mounted on a belt. A majority of the pouches are made from leather or nylon.

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Finish

Higher quality multi-tools have a polished finish. This helps to prevent corrosion as compared to some of the other finishes available, like bead blasted.

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Opening Type

There are many ways that multi-tools can be opened. Most require two handed opening. SOG combination tools are famous for their one handed flick opening.

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Weight

The weight of a multi-tool is something else to consider. Keep in mind that the heavier tools will usually have many more components, be much stronger, and/or be capable of bigger chores.

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