Knives have a unique language all their own. To fully understand them and their many unique features, it helps to be fluent in that language.

This glossary provides a comprehensive guide to all the most important terms, acronyms, and abbreviations used in the cutlery industry. Some are specific to Spyderco products and the unique features we incorporate into them, while others apply to all knives, sheaths, and production methods, regardless of the manufacturer.

By becoming familiar with these terms, you can better understand the design, construction, technology, materials, and unique features of your knives.

The deeper your understanding of your knives, the more you will appreciate and enjoy them.

ABS - A black amorphous thermoplastic polymer with high impact strength.

Almite - A coating used on aluminum handles similar to anodizing. Resistant to scratching and marring, it can also be tinted to any color for visual appeal.

Alumina Ceramic - The compound used in Spyderco sharpening stones. It consists of a ceramic-bonding agent mixed with alumina particles (synthetic sapphires) that is shaped and kiln fired at temperatures in excess of 3000 degrees F.

Ambidextrous - Using both hands with equal ease. Pertaining to knives, it is a knife that can be operated equally well with both the left and right hand.

Anodize - To subject a metal to electrolytic action as the anode of a cell in order to coat with a protective or decorative film.

Austenite - A solid solution of carbon or of carbon and other elements in gamma iron, having a face-centered cubic lattice at all temperatures.

Austenitic Steel - A major class of alloy steel, especially stainless, composed primarily of austenite. Unlike martensitic steels, which are hardened through heat
treating, austenitic steels work harden.

Balisong/Butterfly - A knife design believed to have originated in the UK and later popularized in the Philippines. Often used in the Filipino martial arts, it consists of two handles that rotate in opposite directions to completely enclose the blade or lock it in the open position.

BaliYo® - A skill-based toy inspired by the Filipino balisong (“butterfly”) knife that combines ahigh-performance pen and two handles that each rotate 180 degrees. With practice, the weighted, precision-balanced handles can be flipped, swung, twirled, and spun in a variety of patterns, transforming an everyday writing tool into a fascinating game of skill.

Bead Blasted - A finish achieved by bead blasting, a form of abrasive blasting that uses fine glass beads as an abrasive medium. Abrasive blasting is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth, roughen, shape, or clean a surface.

Bolster - A piece of metal, generally nickel silver or stainless steel, that is located at one or both ends of a folding knife handle.

Boltaron® - A recycled ABS/acrylic PVS extruded alloy sheet material used for making sheaths. A moldable thermoplastic, it has excellent impact strength and is resistant to chemicals and abrasion. Similar to Kydex®.

C.Q.I. - Constant Quality Improvement-a process Spyderco applies to product design and manufacture in which changes and refinements are continually made to existing models, improving ergonomics, materials or manufacturing techniques.

Caping - The careful and detailed removal of the hide of a game animal for the purpose of taxidermy. More precisely it refers to the removal of the skin from the head, shoulders and neck.

Carbide - A hard, sharp carbon/iron material typically used in tools for the machining or drilling of steel. Spyderco uses carbide to make the glass-breaker tip of the C79 Assist model.

Choil - A small scallop or cutout between the cutting edge and the ricasso of the blade that allows the edge to be sharpened all the way to the shoulder of the ricasso.

Choil Jimping - Small grooves machined into the edge of a choil to provide added purchase, control and slip resistance.

CLIPIT® - Spyderco's trademarked term for their line of folding knives that feature a pocket clip. A CLIPIT fan is often called a CLIPITEER.

ClipJoint - A non-locking, clip-carried folder specifically designed for two-handed operation. Unlike SLIPIT knives, ClipJoint knives cannot be opened one-handed.

Cobra Hood™ - A machined flange or shroud positioned over the Spyderco round opening hole on the spine of a blade. It provides increased surface area and a positive purchase when opening the blade one-handed. Ideal for use with
gloved hands, this feature is currently used on Spyderco's C79 Assist rescue knife.

Cordura® - Cordura® is a family
of fabrics made from yarns or fibers from INVISTA. It is used in a wide range of products, including luggage, backpacks, boots, military wear, and performance apparel because it is very durable and abrasion resistant. Spyderco uses Cordura in our SpyderPacs and in the sheath of our Warrior knife.

Corrosion - A process in which a solid, especially a metal, is eaten away and changed by a chemical reaction. 

Cubic Boron Nitride (CBN) - The second-hardest material after synthetic diamond, CBN is synthesized from hexagonal boron nitride under conditions similar to those used to produce synthetic diamond from graphite. As an abrasive, its primary advantages are its high thermal stability and chemical resistance, allowing it to maintain its hardness at high temperatures. This makes it ideal for machining ferrous materials. 

Damascus Steel - A steel produced by forge welding layers, rods, or strands of steel to create a homogenous piece. Nonferrous metals are sometimes also included in this process. After final shaping, parts made from Damascus steel are typically etched to highlight the steel’s pattern.

David Boye Dent - Custom knife-maker David Boye removed a small arc or dent of metal from the lock bar lever of his knives. This modification, adopted by Spyderco, reduces the possibility of gripping the handle hard enough to depress the lock bar and accidentally unlock the blade during use.

Detent - A minute divot or dimple machined into the tang of a folding knife blade. A ball bearing seated in the surface of the Liner Lock drops into the detent hole when the knife is in the closed position to hold the knife blade closed inside the handle.

Diamond Coating - The mechanical entrapment of diamond crystals into a metal substrate. Used in the production of sharpening devices, this process is done by depositing metal, layer by layer, from a plating solution until enough
material is built up around the diamond crystals to hold them in place.

DLC Coating - DLC (Diamond-like carbon) is a mixture of sp2 (graphite) & sp3 (diamond) used for coating blades and parts to make them non-reflective and increase their wear resistance and corrosion resistance.

EDC - An acronym for 'everyday carry,' indicating a knife that is carried and used daily.

ELU - An acronym for 'end-line user,' the consumer who uses Spyderco knives and sharpeners.

Embellishment - A term used to describe personalized engraving or additional ornamentation added to a knife after it is manufactured.

Emerson Opening Feature - A blade opening device invented and patented by Ernest Emerson of Emerson Knives. It consists of an integral hook protruding from the blade's spine that catches the edge of the pocket when the knife is drawn to automatically open the blade. Licensed from Ernest Emerson.

Ergonomics - An applied science concerned with designing and arranging things people use to maximize safety and efficiency. Knives that are designed to be comfortable and less fatiguing to use are considered ergonomic.

False Edge - Originally a term that referred to the upper edge of a sword that faced back toward the user and was used in reverse or “back” cutting tactics. When applied to knives, it refers to a section of sharpened edge on the back of the knife near the tip. It is sometimes used interchangeably with “swedge” to describe an unsharpened bevel on the back of the blade.

Finger Choil - A cutout or scallop in the profile of a knife at the juncture of the
handle and blade that provides a purchase for the finger when gripped. On non-locking SLIPIT knives, this feature also helps prevent accidental blade closure during use.

Flash Batch™ - A new knife design not previously produced by Spyderco, a Flash Batch is a limited edition production run with each knife in the run individually numbered. Once manufactured, Flash Batch models will not be produced again. 

Flipper - A small integral tab near the tang of a folding knife blade that extends from the back of the handle when the knife is closed. Invented by custom knifemaker and Cutlery Hall of Fame member Kit Carson, it provides leverage that allows the blade to be opened with a stroke of the index finger 

G-Clip - An adjustable thermoplastic clip affixed to fixed-blade sheaths to
support a variety of carry positions on the belt, waistband, or other locations.

Handguard - A protrusion or expansion of a knife's handle proximal to the blade that prevents the hand from sliding forward onto the edge.

High Alumina Ceramic - The compound used in the manufacture of Spyderco sharpening stones. It consists of a ceramic-bonding agent mixed with alumina particles (synthetic sapphires) that is shaped then kiln fired at temperatures in
excess of 3000 degrees F.

Inlay - To ornament an object by embedding a piece of a different material in it, flush with its surface, or the piece of material inlaid into an object.

Jimping - Grooves on the edge of the tang, spine, or other surface of a knife that provide texture for increased control during use.

Kick - The unsharpened portion on the underside of a knife blade adjacent to the edge. The kick prevents the edge from touching the inside of the handle when closed.

Kraton® - A high-performance
elastomer manufactured by Kraton Polymers used as a synthetic replacement for rubber. Kraton provides the flexibility, high traction, and sealing abilities of natural rubber, but with increased resistance to heat, weathering, and chemicals. Kraton is used in the manufacture of knife handles to provide a comfortable, secure grip.

Kydex® - A thin thermoplastic material commonly used for firearm holsters and knife sheaths. It can be easily heat formed, yet is flexible, durable, and resistant to perspiration, chemicals, oils and solvents.

Lanyard - A cord passed around the neck, wrist, or other anchor point for holding a knife or other object.

Lanyard Hole - A small hole in a knife's handle through which a cord or lanyard may be threaded. Lanyards provide additional security during use of a knife and help prevent dropping or loss, especially around water.

Left/Right-Hand Carry - The ability of a knife clip to be attached to either side of the handle to support mirror image carry on both the left and right sides of the body.

Liner - A thin, flat metal plate that provides the primary structure for the handle of a folding knife. Liners are typically used in pairs.

Little Big Knife - A term coined by Spyderco to describe a small-bladed knife (generally under three inches)
that is manufactured using features and materials that allow the knife to be used for strenuous cutting tasks normally only performed with larger, heavier tools.

Martensite - A solid solution of carbon in alpha-iron that is formed when steel is cooled so rapidly that the change from austenite to pearlite is suppressed; responsible for the hardness of quenched steel.

Martensitic Steel - A steel composed primarily of martensite, a crystalline structure created when the steel in subjected to a heat-treating process in which it is heated to critical temperature and rapidly cooled or quenched to harden it.

MIM - An acronym for Metal Injection
Molding—a process in which a powdered metal is mixed with a binder and injected into a mold to create a detailed molded part.

MOLLE - An acronym for Modular Lightweight Load-carrying Equipment — the current system of load-bearing equipment used by military and law enforcement personnel. It consists of a grid of nylon webbing that allows the
modular attachment of pouches and other equipment to achieve customized mission-specific configurations.

Nesting - The practice of machining a recess into G-10 or other handle scale
material to inlay the liners and lock mechanism. Nesting increases structural strength while reducing the overall thickness of the handle.

Nonferrous - Relating to or denoting a metal other than iron or steel.

Obverse - The side of a coin or medal bearing the head or principal design. When applied to knives, it is the side of the knife visible when viewed edge down with the point facing to the left. 

OpFocus® - Short for “operational focus,” a term coined by Spyderco that is roughly synonymous with “tactical.” It is also the name of our professional purchase program for military, law enforcement, and first-responder personnel. 

Phosphor Bronze Washers - Washers placed over a knife's pivot pin between the between the scales or liners and the blade. They are made of phosphor bronze alloy, which provides a low-friction bearing surface for smooth operation.

Pommel - The knob or expansion found at the butt end of a knife handle.

Powdered Metallurgy - An advanced manufacturing process that uses a high-pressure gas to atomize molten steel into a spray that rapidly cools it into a fine powder. This prevents the alloys within the steel from segregating and ensures an exceptionally fine, uniform grain structure. The powdered steel is then re-heated in high-pressure containers to create ingots that are rolled to toughen the steel and mill it into finished form.

Quillion - A hand guard protruding from one or both sides of a knife at the
juncture of the handle and blade. Its purpose is to prevent the hand from sliding forward onto the blade during use.

Reverse (aka Pile Side) - The side of a knife opposite the obverse side. It is visible when the knife is viewed edge down with the point facing to the right.

Satin Finish - An attractive finish applied to metal that involves using an abrasive to create a series of fine parallel lines across the material’s surface.

Scale - A slab of material used as part of a knife handle. Handles typically
have two scales that are riveted, screwed or bonded to the tang of the blade.

Skeletonized Liners - Internal steel handle liners that feature a series of holes (skeletonizing) that reduces their weight while maintaining strength and rigidity.

Slip Joint - A non-locking folding knife with a blade that is held open by spring tension. Slip joint knives do not have pocket clips.

SLIPIT - Spyderco and byrd folding knives with non-locking blades that are held open via a notched joint. SLIPIT knives are equipped with pocket clips, while slip-joint knives are not.

Spine Cusp - A ridge or crest above the Spyderco Round Hole that creates a shelf for the thumb to apply pressure during use.

Spine Jimping - Small textured grooves on the spine of a blade that provide a tactile index, add purchase, and increase slip resistance.

Sprint Run® - A limited, one-time-only production of a specific knife design or variant. Production quantities of sprint runs are limited.

Spyder-Drop Opening - A one-handed opening method that involves grasping the closed blade of a folding knife near the pivot pin and swinging the handle down to open the knife. It is best accomplished with a Spyderco knife, using the Spyderco Round Hole to achieve a secure grip.

Spyderco Trademark Round Hole™ - A round hole in a knife blade that is used for ambidextrous one-handed opening of the blade. In fixed-blade knives, it also serves as a forward-positioned lanyard hole.

Stepped Pivot - A folding knife pivot that features right-angle “steps” or shoulders between sections of different diameters. Most commonly, the center of the pivot is larger in diameter than the two ends. This pivot style provides increased strength and ease of assembly during manufacturing. 

Stonewashed Finish - As it applies to knives, a dull matte finish on a metal part produced by a tumbling or vibratory process using a coarse polishing medium. 

Swedge - A beveled section on the spine of a blade that reduces weight, adds style, and provides a more acute point. Unlike a false edge, a swedge is unsharpened.

Tang - The portion of a blade that connects to the handle or serves as the foundation of the handle of a knife.

Tip-Up/Tip-Down - Terms of reference that describe the position of the blade of a closed knife when it is clipped to a pocket. The attachment of the clip to the handle of the knife determines whether it is positioned tip-up or tip-down.

Titanium - A non-ferrous metal that
is lightweight, highly corrosion resistant and has a high degree of tensile strength. It is ideally suited to use in the handles, liners and other components of folding knives.

Tumbled Finish - A surface finish applied to a component by tumbling it with various types of polishing media.

Zome - Zome (pronounced “zoh-may”) is a class of Japanese handicrafts that specializes in dyeing textiles using dyes derived from plants, flowers, fruit, and other natural sources. Spyderco’s Zome knife handles use a technique similar to traditional hiki-zome (brush dyeing) to hand brush various colors of dye onto the handles to create distinctive, one-of-a-kind patterns.