Knives are one of the oldest manmade tools in existence, dating back to the stone age. Still widely used and carried today, knives have massively evolved over the last 2.6 million years, giving way to a wide variety of increasingly complex blades designed for taking on specific tasks. And while the primary parts that make up a knife are well-known and understood, falling into the category of common household knowledge, far fewer are privy to the more intricate, technical aspects of modern knives. So, with this in mind, we’ve opted to take a deep dive into the components and anatomy of contemporary blades to deliver this guide to the key terms and phrases that every knife owner and enthusiast should know.
Action: This term refers to the deployment of the blade on a folding knife. More premium knives have smoother actions that are typically helped along by ball bearings and detents. Actions can also be manual or automatic.
Arc Lock: This is a proprietary locking mechanism from knife brand Studies and Observations Group — more commonly known as “SOG.” Using a slide-lock setup, this mechanism is similar to Benchmade’s AXIS lock, though curves — or arcs (hence the name) — in a way that’s similar to the mechanism on most bolt-action pens.
AXIS Lock: One of the most sturdy and revered — and commonly replicated — knife locking mechanisms of all time, the AXIS lock is Benchmade’s own proprietary sliding lock mechanism. First introduced in 1988, this design was originally invented and patented by knifemakers Jason Williams and Bill McHenry before being purchased by the Oregon City outfit and renamed the AXIS lock.
Back: Not to be confused with a swedge or spine, a knife’s back is the unsharpened side of a blade with a single edge.
Base: This word describes the bottom of a blade where the knife steel meets the handle.
Bail: Looking somewhat like a tiny closed-off horseshoe, a bail is a small metal loop that runs through a hole on the bottom of a knife’s handle, allowing it to be connected to keychains, carabiners, or whatever else.
Balisong: Originating in the Philippines, a balisong is a unique type of folding knife that’s comprised of two handles — the “bite handle” (i.e. the one covering the sharpened side of the blade) and the “safe handle” (i.e. the handle covering the blade’s back) — that connect to the base of the blade and counter-rotate around it in order to either keep the blade covered or act as a single handle. Also known as a Batangas knife, a fan knife, or a butterfly knife — the latter of which “balisong” directly translates to — these knives are illegal to carry in quite a few regions.
Belly: The term “belly” — or “blade belly” — refers to the curved portion toward the front of the blade that’s used for cutting and slicing.
Bevel: A “bevel” is the area on a blade that has been ground down to create an edge for cutting and slicing. Knives’ blades can either be single-beveled or dual/double-beveled.
Bolster: Found just above a knife’s guard, a “bolster” is a piece of metal extending out from the bottom of the blade to the handle. Also commonly found on kitchen knives, bolsters can afford a knife additional strength, while also protecting the fingers of its user. These items can also be added for decorative purposes.
Butt: This term simply refers to the bottom or end of a knife’s handle.
Button Lock: This is a type of locking mechanism consisting of a — typically circular — push-button that’s used to disengage the blade from its locked position. These items look very similar to the buttons used to deploy the blade on a lot of automatic knives.
Choil: A “choil” is the small unsharpened section of a blade just before it meets the handle — or bolster.
Clip Point: A clip point is a common type of blade shape where a section of the front of the spine has been removed or “clipped off.” Though the cutting edge and belly on a clip point blade share a similar profile to that of a drop point knife, part of the spine features a straight or concave cutout that affords it better piercing abilities.
Compression Lock: An extremely strong type of locking mechanism patented by Spyderco and used on many of its most popular knives, a compression lock utilizes a “leaf-like spring” from a split liner in the handle that wedges itself laterally between a ramp on the blade tang and the stop pin — or “anvil pin.”
CPM: Short for “Crucible Particle Metallurgy,” CPM is a powder metallurgy technology first patented in 1970. Used to create many of today’s most premium blade steels, CPM combines additional chemicals and elements into the alloy which allows for markedly stronger blade steels with incredible edge retention.
CruWear: This is a proprietary blade steel from Crucible Industries that is basically a more premium version of D2 steel that boasts greater toughness and superior wear resistance.
CV: Standing for “Chrome Vanadium,” CV is a type of blade steel that’s rich in chromium and vanadium. While it is a solid construction, CV blade steels do typically require an ultra-thin oil film be kept on the blade at all times in order to maintain the steel’s finish.
Damascus: Taking its name from the capital city of Syria where this material was originally produced centuries ago, Damascus is a type of blade steel that’s comprised of two different alloys that are repeatedly folded and tempered, resulting in a variety of unique patterns. The quality of Damascus steel will ultimately depend on the two alloys that make up its composition, however, Damascus steel is popularly used on many of today’s more high-end EDC knives.
Damasteel: Based in Söderfors, Sweden, Damasteel is a company that produces its own proprietary, high-end — and thoroughly modern takes on — Damascus steels using a patented metallurgy process.
Detent: A component used in folding knives with liner or frame locks, a “detent” is a tiny ceramic or steel ball bearing that raises up when the blade is deployed and falls back into a hole when closed, thereby providing some resistance in order to keep the knife closed and prevent accidental deployment — while also not mitigating the smoothness of the knife’s action.
Drop Point: Almost certainly the most commonly-used blade shape in existence, a drop point describes the silhouette of a blade with a convex spine that slowly tapers from the base of the blade to its point. Because of their robust shape, these blades offer great durability, and their ample belly and cutting surface affords ample real-world utility — explaining this blade shape’s ubiquity in both the EDC and fixed blade knife spaces.
False Edge: This word describes an unsharpened edge of a blade that’s been given the appearance of a beveled edge. False edges are common on dagger-style knives with a single beveled edge.
Fixed Blade: This describes a rigid, non-folding knife. These knives are often comprised of a single piece of metal that runs the entire length of both the blade and handle — a setup known as a “full-tang” knife.
Flipper: A “flipper” can refer to either a style of folding knife where the blade is deployed by flipping a nib on the blade, or the actual flipper tab itself.
Frame Lock: This is a type of ultra-sturdy locking mechanism where the device has been integrated directly into the knife’s back handle slab — rather than into the liner. This mechanism sees a portion of its lock-bar thinned out, affording the metal just enough flex to accommodate a blade’s thickness. Frame lock knives also allow users to open or close a knife with only one hand.
Friction Folder: A “friction folder” is a type of folding knife that’s completely devoid of any locking mechanism or detent, and instead relies on the friction between the blade and the inside of the handles in order to keep the blade closed when not in use.
Front Flipper: This is a particular style of flipper knife that differs from regular flipper designs in that its flipper tab is located on the spine of the blade. This setup doesn’t necessarily offer any objective benefits, though some prefer the action and appearance of front flippers.
G-10: Lightweight, dense, compact, and extremely durable, “G-10” is a popular and affordable material that’s often used for knife handle constructions. Completely impervious to water, this material is made by soaking woven fiberglass in an epoxy resin before it’s compressed and baked.
Guard: This aptly-named term refers to the part of a knife’s handle that usually curves outward, providing additional grip and preventing the user’s hand from slipping onto the blade’s edge.
Grind: A “grind” describes the way in which a blade’s edge has been ground in order to achieve a bevel. The most frequently used types on EDC knives are flat or hollow grinds, though saber grinds are fairly common as well — the latter of which is also known as a “v-grind.”
Gut Hook: As its name suggests, a “gut hook” is a section on the spine of some fixed blade knives that’s comprised of a sharpened hook that’s made for field dressing, gutting fish and game, and splitting the skin of game animals.
Hardware: A knife’s “hardware” refers to the screws, bolts, and other small items used to piece together the components that constitute the knife. This term can also sometimes describe a knife’s pivot.
Heat Treating: An incredibly important phase in a blade’s production, “heat treating” is a process in which blade steel is exposed to extreme temperatures, affording it a wildly harder and more durable material. Even when using the most top-shelf blade steels available, without heat-treating, a blade’s durability, finish, and edge retention will massively suffer.
HRC: While the acronym is admittedly a little confusing, “HRC” is short for “Rockwell Hardness Rating” — a scale used to give an objective sense of a knife steel’s hardness.
Inlay: An “inlay” is an often decorative element that’s set in a knife’s handle. Most commonly, handle inlays are composed of high-end precious materials like ivory, carbon fiber, walnut, brass, pearl, or “Timascus” steel.
Integral: This word describes an extremely premium type of folding knife where — rather than being composed of two handle slabs mated via a frame and backspacer — the handle is crafted from a single piece of metal or composite, with aluminum, titanium, and G-10 being three of the most common.
Joint: A knife’s “joint” is the point where the handle and blade are mated via a pivot.
Jimping: The term “jimping” describes the ridged and/or knurled surface often found on a knife’s liner and at the base of a blade’s spine, providing additional grip while also affording some aesthetic flair.
Karambit: Hailing from Indonesia’s West Sumatra region in the eleventh century, a “karambit” is a style of knife that’s modeled after the profile of a tiger claw. In addition to their curved blades, karambits are also characterized by the base of their handle being equipped with an integrated finger loop. There are also both fixed blade and folding karambit knives.
Lanyard Hole: As one might guess from the name, a “lanyard hole” is a small circular cutout at the base or bottom of a knife’s scales that allows a decorative lanyard or paracord to be looped through the handle.
Lever Lock: Dating back roughly a century, lever lock knives are a bygone style of switchblade where the blade is automatically deployed via the flip of a lever — rather than via pushing a button. This same lever is also used to disengage the blade from its locked position.
Liner Lock: Though less robust than frame locks, “liner locks” are another sturdy type of locking mechanism that’s comprised of a lock plate positioned between the inside of the two handle slabs. Like frame locks, liner lock knives can be deployed or closed using just one hand.
Lockback: An old-school type of locking mechanism often found on more traditional folding pocket knives like those from Buck and Case, a “lockback” knife uses a cutout toward the back of the handle’s spine that accommodates a locking plate that secures the blade into place until the plate is pressed in to disengage the lock.
Micarta: Another popular handle construction that’s both incredibly hardwearing and accessibly-priced, “Micarta” is a proprietary brand name material comprised of canvas or linen that’s been soaked in a phenolic resin and then baked.
Nail Nick: An element most commonly used on more traditionally-styled, vintage-inspired folding pocket knives, a “nail nick” describes the small indent in a blade just below the spine that allows users to open the blade using a fingernail.
Neck Knife: A “neck knife” is a small type of fixed blade knife that comes in a sheath and is usually linked to a piece of paracord and worn around the neck beneath the wearer’s shirt or jacket — hence the name “neck knife.”
OTF: A tactical stye of automatic knife, the term “OTF” is simply short for “Out The Front” and describes a spring-loaded blade that is deployed straight out through the top of a knife’s handle at the push of a button or switch — and then retracted via another flick of the same button or switch, albeit sometimes in the opposite direction.
Pivot: The “pivot” on a knife is the piece of hardware that runs through the base of the blade, marrying it to the handle.
Point: This word refers to the very tip — or “point”— of a blade and is frequently accompanied by an additional descriptor, with the most common styles being clip points, drop points, and spear points.
Quillion: A “quillion” is essentially an old-timey name for a knife’s guard.
Ricasso: A “ricasso” describes the point on the blade where the base thickens before meeting with the handle.
Rockwell Scale: The “Rockwell Scale” is used to denote the hardness of blade steel. Anything close to 60 is considered a good rating.
SAK: This is simply an abbreviation for “Swiss Army Knife.”
Sandvik: Used on most Opinel knives, Sandvik is a brand that produces blade steels that, while fairly inexpensive — at least compared to more premium blade steels — offers solid performance, hardness, durability, and edge retention.
Scales: This term refers to a knife’s handle slabs or the large inlay pieces that adorn a handle or its frame.
Serration: This word refers to a jagged, zig-zagging type of blade edge that is markedly better at sawing than straight-edged blades. Quite a few EDC and fixed blade knives feature an edge that’s partially serrated, allowing for the best of both worlds. Sharpening a serrated edge can, however, be tricky.
Sheepsfoot: Another popular blade shape, a “sheepsfoot” blade is characterized by a straight, flat blade with a back that runs parallel to the edge before rounding out at the tip.
Sleipner: Produced by German outfit Böhler, “Sleipner” is a mid-to-high-end blade steel that’s typically used on mid-tier European knives. And while there are plenty of knife models that feature this construction, Sleipner is still one of the more seldom-seen blade steels.
Slipjoint: A classic style of pocket knife, a slipjoint is similar to a friction folder, though it also boasts a spring mechanism that keeps the blade’s spine in place.
Spear Point: As one might infer from the name, a “spear point” is a blade shape that takes inspiration from spears, and as such has an often symmetrical profile that’s similar to that of a dagger. This blade shape is commonly found on fixed blade and OTF models.
Spine: Somewhat interchangeable with the word “back,” a knife’s “spine” refers to the unsharpened backside of the blade, opposite the sharpened edge.
Standoff: A “standoff” is the spacer inside a knife’s handle that protects the blade when closed, shielding it from bending or other damage.
Sweep: The “sweep” on a knife refers to the round cutting edge on a blade. This term is interchangeable with “belly.”
Swedge: A “swedge” is another term for a false edge on a blade, albeit swedges tend to be a little more decorative and elaborate in their design.
Tang: The word “tang” refers to the portion of a knife’s blade that extends into the handle. A “full-tang” knife describes a fixed blade where the blade runs the entire length of the knife, from the butt to the point.
Tanto: Taking influence from the shape of the samurai short swords of the same name, a “tanto” is a blade shape with three sides that meet at extremely angular edges and culminate in a pronounced point.
Terravantium: Terrain 365’s ultra-high-performance and low-maintenance blade steel, “Terravantium” is an insanely premium and rugged material that is completely impervious to corrosion, oxidation, rusting, staining, or pitting, even when left submerged in saltwater.
Thumb Hole: The term “thumb hole” refers to a cutout toward the base of a blade that allows the user to deploy the blade with one hand using their thumb. Alongside its compression lock and unique blade shape, Spyderco is well known for its signature circular thumb hole design.
Thumb Stud: A “thumb stud” is a small nib or barrel set at the base of a blade that enables the user to flick the blade open with one hand. Benchmade famously employs thumb studs on many its folding knives.
Tip-Up / Tip-Down: This term refers to pocket clips and describes the orientation of the blade when the knife is clipped into a pocket. Tip-up pocket clips allow for much faster one-handed access and deployment.
Tri-Ad Lock: A proprietary locking mechanism patented by Cold Steel, a “Tri-Ad Lock” is a unique system that uses a lock bar set along the spine of the handle. In addition to being tested to withstand up to 800lbs of force, another major part of what makes this mechanism unique is its rocker pinhole, which is made with extra space on both sides which allows it to self-adjust as wear and tear occurs over time.
Vanadium: This word describes an element that’s commonly added to blade steels that are created using powder metallurgy technology.
Wharncliffe: Another type of blade shape, a Wharncliffe knife is similar to a sheepsfoot with a straight flat blade, however, the Wharncliffe sports a convex-sloping spine, giving it a finer point that allows for better piercing.
Zytel: First introduced in 1985, “Zytel” is DuPont’s name for a trademarked plastic material that’s composed of fiberglass-reinforced nylon and is sometimes used in handle construction.