Sharpening Dictionary
A
Abrasive
A word for the tiny bits, whether they're from rocks or made by people, on a surface used to make things sharper by rubbing them against it. Examples include Cubic Boron Nitride, Aluminum Oxide, Chromium Oxide
Acute means:
Sharp edge or point.
A smaller angle compared to another. For example, a 15-degree cutting angle is more acute than a 20-degree one.
An angle less than 90 degrees.
Alloy means:
A mix of metallic elements, sometimes with non-metallic ones.Alloys have different properties than pure metals. The mix can be changed to get properties like hardness or resistance to rust. Steel, brass, and bronze are examples of alloys.
Aluminum Oxide is:
A crystal made of two Aluminum and three Oxygen atoms. It's used to sharpen tools, often in stones, compounds, or powders. Also known as Alumina or Corundum.
Aluminum Oxide Stone is:
A sharpening stone crafted with aluminum oxide as the abrasive.
It's also a term used for sharpening stones similar to India Stones but not made by Saint-Gobain Abrasives, Inc. / Norton Abrasives, so they can't be called by that trademarked name.
Angle
The shape of an edge made by where two bevels meet.
The measure in degrees of how the edge looks from the side.
In knife sharpening, angle talks about how each bevel relates to the center line of the blade. Usually, it's half of the total angle of the knife's edge. For instance, if a knife's edge is 30 degrees overall, each bevel might be called 15 degrees relative to the knife's center line.
Arkansas Stone:
A natural rock taken from Ozark novaculite (silicon quartz).Arkansas Stones have a special crystal structure. They not only sharpen but also polish while sharpening, giving a smooth, sharp edge. These stones come in different grades based on how tightly packed their crystals are, measured by specific gravity. The less dense stones are rougher, while the denser ones are smoother. The grades from rough to smooth are: Washita, Soft Arkansas, Hard Arkansas, Hard Black, and Hard Translucent Arkansas.
B
Belgian Blue Whetstone:
A natural stone utilized for sharpening purposes. Recognized by a high density of spessartite garnets, giving them a bluish-purple hue due to iron content. When used with water, they create a slushy substance during sharpening. Similar to Coticule Whetstones, often located nearby in geological formations. Sometimes, these stones are naturally fused together in adjacent layers. Named after Belgium, the country where they are mined. Often abbreviated as BBW.
Bench Stone:
An abrasive tool shaped like a block, employed for sharpening knives, tools, and similar items. Usually denotes a stone of a manageable size, suitable for placement on a workbench or similar surface for ease of use, contrasting with smaller stones designed to be held by hand.
Bevel:
The angle or slant of a line or surface where it meets another at any angle other than 90 degrees. One of the surfaces that come together to create an edge.
Burnisher:
A tool, typically with a smooth and hard surface, often round or oval in shape, used for turning over a burr on scrapers.
Burr:
A rough, jagged piece of metal that forms on an edge due to abrasion or burnishing. It typically develops on the opposite side of the edge that is in contact with the sharpening or burnishing surface. The presence of a burr can indicate progress in sharpening, signaling a sharp intersection of two bevels. In the case of knives and cutting tools, the burr is usually removed as the last step of sharpening. However, on scrapers, the burr serves as the cutting edge of the tool and is intentionally retained.
C
CBN:
Short for cubic boron nitride, which is a particular crystalline structure of boron nitride utilized as an abrasive. It comprises an equal number of boron and nitrogen atoms and possesses a hardness ranking just below that of diamond. Primarily employed as an abrasive on grinding wheels designed for high-speed sharpening of steel.
Camber:
An arch or convexity along the length of an edge, commonly observed in woodworking hand plane blades.
Carbide:
The abbreviated term for Tungsten Carbide, a compound composed of tungsten and carbon, prized for its exceptional hardness and ability to withstand high temperatures. It is utilized in the manufacturing of cutting tools. Sharpening tungsten carbide cutting tools demands highly durable abrasives like diamond or cubic boron nitride.
Carbon Steel:
Any type of steel where carbon serves as the primary alloying element. Generally, higher carbon levels result in harder steel. Alternatively, it refers to any steel that lacks stainless properties.
Carborundum:
A trademarked term representing various synthetic crystalline substances utilized as abrasives, notably those containing silicon carbide. The trademark is presently owned by Saint-Gobain Abrasives, Inc., the parent entity of Norton Abrasives.
Carborundum Stone:
A trademarked designation for a stone crafted with Carborundum as its abrasive component.
Ceramic Knife:
A knife featuring a blade composed of ceramic material, commonly zirconium dioxide, rather than the typical steel. Ceramic blades exhibit exceptional hardness and edge retention, often surpassing that of steel. Nevertheless, they pose challenges for sharpening, typically necessitating the application of diamond abrasives.
Ceramic Stone:
Also known as Ceramic Honing Stone or Ceramic Sharpening Stone, it's a stone crafted as a fused block or rod from ceramic material. Ceramic Stones are highly durable and typically employed dry, without the use of oil or water as a cutting fluid. They come in medium, fine, and ultra-fine variants, which approximately correspond to 600, 1200, and 2000 grits, respectively. It's important to note that Ceramic Stones differ from Ceramic Water Stones and should not be mistaken for them.
Ceramic Water Stone:
A Ceramic Water Stone, a subtype of Water Stone, is a composite ceramic product where individual pieces of ceramic abrasive material are bound together with a resin binder. Like other water stones, they are employed with water as a cutting fluid, but they are more durable than other water stones and do not need soaking before use. They range in grit size from 122.5 microns/120 grit to 0.49 microns/30,000 grit. It's essential to differentiate Ceramic Water Stones from Ceramic Stones, as they are not identical.
Chromium Oxide:
Chromium Oxide is a compound made up of 2 chromium and 3 oxygen atoms, forming hard crystals. It's commonly utilized as an abrasive due to its abrasive properties. The color of chromium oxide is green, and it's frequently employed as a pigment as well. Honing compounds containing chromium oxide are commonly known as green honing paste or green rouge. It's one of the constituents in our Green Honing Compound.
Concave:
Concave describes a curved surface or line resembling the interior of a circle or dipping lower in the middle than at its edges or ends. For example, the top side of a spoon is concave. It often denotes a bevel that curves inward in cross-section, usually formed on a grinding wheel. It can also indicate an edge with a curved, inwardly dipping shape along its length.
Concave Grind:
Concave Grind refers to a bevel shaped inward, creating a concave profile in cross-section, unlike a flat or convex surface. Typically, this grind is achieved using a grinding wheel.
Continuous Surface:
A Continuous Surface denotes a diamond sharpening stone where the diamonds uniformly cover the entire area without any gaps or breaks. This type of surface is beneficial for sharpening small or finely pointed tools, as there are no interruptions where tools could catch.
Convex:
Convex refers to a surface or line that curves outward, resembling the exterior of a circle, or is higher in the middle than at its edges or ends. For instance, the back side of a spoon exhibits convex curvature. Typically, Convex indicates a bevel that curves outward in cross-section. It can also describe an edge with a convex curve along its length.
Convex Grind:
A Convex Grind denotes a bevel that is shaped to be convex in cross-section, contrasting with flat or concave shapes. Typically, it is crafted using a belt grinder. This type of grind creates a curve that bulges outward from the blade, enhancing strength and durability.
Coticule Whetstone:
A Coticule Whetstone is a natural stone utilized for sharpening purposes, distinguished by its high concentration of spessartite garnets and its distinct white-yellow hue. These stones are somewhat fragile and are commonly mounted onto a separate slate piece to prevent damage; however, the slate does not participate in the sharpening process but merely provides structural support. When employed with water during sharpening, they generate a slurry. Quarried in Belgium, they are often found in proximity to Belgian Blue Whetstones, with occasional natural interlocking layers between the two types.
Crystolon Stone:
Crystolon Stone is a trademarked term denoting specific sharpening stones crafted by Saint-Gobain, Inc./Norton Abrasives. These stones, designed for use with oil, are commonly composed of silicon carbide abrasives, renowned for their rapid cutting ability. They are among the quickest cutting oil stones available. Crystolon stones exhibit a gray color and are softer and more prone to wear than India Stones. They are offered in coarse (120 grit), medium (180 grit), and fine (320 grit) variants.
Cubic Boron Nitride (CBN):
Cubic Boron Nitride (CBN) refers to a precise crystalline configuration of boron nitride employed as an abrasive. It comprises an equal ratio of boron and nitrogen atoms and possesses a hardness surpassed only by diamond. Primarily, CBN serves as an abrasive on grinding wheels intended for rapidly sharpening steel. Occasionally abbreviated as CBN for convenience.
Cutting Angle:
The Cutting Angle signifies the angle formed by the meeting of the bevels, defining an edge, usually measured in degrees. It distinguishes from the sharpening angle by encompassing both bevels' angles concerning the blade's centerline. This distinction is common in knife sharpening scenarios, where the sharpening angle refers to each bevel's relation to the blade's centerline. Sometimes referred to as the inclusive angle.
Cutting Fluid:
Cutting Fluid is a liquid employed in sharpening tasks to remove swarf and prevent the sharpening stone from clogging. Typically, water or oil is utilized for this purpose.
D
Damascus Steel:
Damascus Steel originally denoted a type of steel produced in different Asian regions around 700 - 1000, prized for its exceptional flexibility and edge retention. This steel showcased a unique wavy or water-like pattern of lines visible post-forging. Today, Damascus Steel refers to any steel pattern-forged to create visible lines within the steel body. It no longer necessarily implies specific hardness or flexibility characteristics.
Diamond:
Diamond is a crystalline form of pure carbon employed as an abrasive. It stands as the hardest mineral known. Utilized in sharpening stones and grinding wheels, particularly valued for durability and its capacity to cut extremely hard metals. It serves as the primary abrasive for sharpening carbide.
Diamond Stone:
A diamond stone typically consists of a metal plate or a stone with a layer of small diamonds attached to its surface. Primarily used for sharpening knives, tools, and similar items. The key benefits of diamond stones include their rapid cutting action facilitated by the diamonds and, in the case of metal plate-mounted diamond stones, the maintenance of flatness over time.
E
Edge:
Edge is not sharp; it's flat or An edge with a 20-degree cutting angle is higher than one with a 15-degree cutting angle.
F
Flat Grind:
A flat grind is a bevel that is flat in cross-section, unlike a convex or concave grind.
Flattening Stone:
A flattening stone is a plate or stone with abrasive properties used to flatten or resurface a sharpening stone.
Fleam:
The leading edge of a saw tooth. An old-fashioned surgical tool employed for drawing blood.
G
Grind:
To remove material or sharpen by abrasion, typically using an abrasive wheel. The cross-sectional shape of one or more of the bevels that form an edge. Examples include flat grind, convex grind, concave grind.
Grinding Wheel:
Any of numerous types of sharpening stones shaped like a wheel or disk and made of abrasive material.
Grit:
A general term for the tiny particles used in sharpening. The numerical measurement indicating the size of particles in an abrasive material. It describes the number of openings per linear unit in a screen used to sort particles. Lower grit numbers represent coarser particles, while higher grit numbers represent finer particles.
H
Hard Arkansas Stone:
An Arkansas Stone with a specific gravity ranging from 2.30 to 2.45. Hard Arkansas Stones are denser and finer compared to Washita Stones and Soft Arkansas Stones. However, they are less dense and coarser than Hard Black Arkansas or Hard Translucent Arkansas stones. These stones are roughly equivalent to 800 to 1000 grit. Their color may vary, including gray, white, pink, black, or combinations thereof, but color is not a factor in grading; only specific gravity is considered.
Hard Translucent Arkansas Stone:
A type of Arkansas Stone with a specific gravity of 2.5 or higher, typically white or gray in color with possible streaks of other colors, and allowing some light to pass through it. Hard Translucent Arkansas Stones are denser and finer than Washita Stones, Soft Arkansas Stones, and Hard Arkansas Stones, but share a similar density and fineness with Hard Black Arkansas Stones. They are roughly equivalent to 1200 grit or higher. Color is a factor in selecting Hard Translucent Arkansas Stones.
High-Speed Steel:
High-speed steel refers to various types of tool steel designed to maintain their hardness even at elevated temperatures. These cutting tools are utilized in environments with high levels of heat or friction, such as lathe turning. High-speed steel is occasionally abbreviated as HSS.
Hollow Grind:
Hollow grind refers to a bevel that has been crafted on a grinding wheel, resulting in a concave shape in cross-section rather than being flat or convex. Additionally, hollow grind can also denote the process of creating such a bevel.
Hone:
A hone refers to a fine-grained whetstone used to achieve a sharp edge on a cutting tool. It also signifies the act of sharpening on such a fine-grained whetstone. Sometimes, "hone" is casually used to describe the process of sharpening itself.
Honing Compound:
A honing compound is a fine abrasive, either in powder form or mixed with a medium like wax to create a bar or paste. It is employed for polishing an edge.
Honing Paste:
Honing paste is a fine abrasive mixed with a medium like wax to form a paste. It is employed for polishing an edge. Honing pastes are frequently utilized with a strop
Honing Powder:
Honing powder consists of fine abrasive particles in powder form. It is utilized for polishing an edge. Honing powder is commonly applied with a strop.
Honing Guide:
A honing guide is a tool used to keep a tool or knife steady while sharpening, which helps maintain a consistent bevel angle. This ensures efficiency and uniformity in sharpening.
Honing Oil:
Honing oil is a liquid, typically mineral oil, that does not harden. It is used as a cutting fluid when sharpening with oil stones.
I
Inclusive Angle:
The inclusive angle refers to the angle of the intersection of the bevels that create an edge, measured in degrees. It helps to distinguish the overall angle from the sharpening angle, especially in cases where the sharpening angle is described concerning each bevel's relation to the center line of the blade. In such instances, the inclusive angle is the sum of the sharpening angles. This terminology is commonly used in knife sharpening. It is also known as the cutting angle.
India Stone:
India Stone refers to a trademarked name for specific stones produced by Saint-Gobain Abrasives, Inc / Norton Abrasives. These stones are oil stones made with aluminum oxide abrasive. They are recognized for their durability and slower wear compared to Crystolon Stones. However, they are also slower cutting. India Stones typically have an orange/brown color. They come in various grits, including coarse 150 grit, medium 240 grit, and fine 400 grit.
Interrupted Surface:
Interrupted Surface refers to a diamond sharpening stone where the surface is covered with diamonds but contains periodic voids. These voids serve to trap metal debris during sharpening.
Iron:
Iron is a flexible and bendable metallic element used as a base in alloys to create steel for making cutting tools.
L
Lapping Plate:
A lapping plate is a flat, abrasive surface or stone used to flatten or smooth out a sharpening stone.
Lapping Stone:
A lapping stone is an abrasive plate or stone utilized to flatten or smooth a sharpening stone's surface.
M
Mesh:
Mesh refers to the numerical term used to describe the quantity of openings per linear unit in a screen employed to sort particles; it is a measure of abrasive grains. Lower mesh numbers indicate coarser grains, whereas higher mesh numbers denote finer grains.
Micron:
A micron is a unit of measurement equivalent to one millionth of a meter or one thousandth of a millimeter. It is occasionally utilized to gauge abrasive particles. The higher the micron number, the coarser the abrasive, whereas the lower the micron number, the finer the abrasive. Micron is abbreviated as "μm."
N
Nagura:
"Nagura" is the Japanese term for any stone used to create an abrasive slurry or clean the surface of another sharpening stone.
Novaculite:
Novaculite is a type of fine-grained sedimentary rock that contains microcrystalline quartz. Arkansas Stones are crafted from Novaculite.
O
Obtuse
1. having an edge that is not pointed, blunt.
2. having an angle that is higher as compared to another angle. An edge with a 20 degree cutting angle is more obtuse than an edge with a 15 degree cutting angle.
3. having an angle more than 90 degrees.
Oil Stone:
A stone crafted from one of three materials: novaculite, aluminum oxide, or silicon carbide, utilizing oil to eliminate swarf. Arkansas Stones, Crystolon Stones, and India Stones are all Oil Stones. The oil stone's prime advantages are its solid performance and reasonable price.
Overall Angle:
The angle formed by the intersection of the bevels that create an edge, measured in degrees. The term overall angle distinguishes the complete angle from the sharpening angle in cases where the sharpening angle is described as the relationship of each bevel to the center line of the blade. In such instances, the overall angle is the total of the sharpening angles. This scenario is commonly encountered in knife sharpening. It is sometimes referred to as the cutting angle or inclusive
P
Plane Iron
The cutting blade of a woodworking hand plane.
Polish:
To create a smooth and shiny surface through friction. To refine sharpness using extremely fine-grit abrasives after coarser abrasives have been employed to establish an edge.
R
Razor Strop
A type of strop consisting of a belt or strap of leather or fabric used by anchoring one end to a fixed point and grasping the other by hand to pull the belt taut. Razor Strops may be used with or without honing compound applied to their surface. The name Razor Strop reflects this type of strop's close association with preparing straight razors for shaving.
Rockwell Scale:
A method for measuring the relative hardness of materials by assessing the depth of indentation made by a standard indenter under a predetermined load. Different Rockwell scales are utilized for different materials, each identified by a letter designation. The C scale, denoted as Rockwell C or HRC followed by a number, is employed for assessing the hardness of steels. A higher numerical value on the scale corresponds to greater hardness. In the context of knives and woodworking tools, Rockwell values generally range from the 50s to the mid-60s.
S
Serrated
Having a notched edge or sawlike teeth.
SharpeningThe process of making an edge.
Sharpening Angle:The angle at which a tool is positioned in relation to the sharpening stone, determining the degree of inclination. The angle to which an edge is honed during the sharpening process. In knife sharpening, the angle formed between the knife and the sharpening stone, relative to the center line of the knife. Often half of the overall angle of the knife's edge. For instance, if a knife has an overall edge angle of 30 degrees, the sharpening angle is typically referred to as 15 degrees.
Sharpening Guide:
A tool or device designed to stabilize a knife or tool during sharpening, ensuring a consistent bevel angle for efficient sharpening.
Sharpening Stone:
A block-shaped abrasive product utilized for sharpening knives, tools, and other cutting implements.
Silicon Carbide:
A highly rigid blue-black crystalline substance composed of one Silicon atom and one Carbon atom. Employed as an abrasive in sharpening stones, powders, and compounds.
Silicon Carbide Stone
A stone manufactured with Silicon Carbide Abrasive.
Sink Bridge:
A holder crafted to accommodate stones, devised to fit atop a sink. Sink Bridges prove especially handy with water stones, as sharpening over a sink allows for easy access to water and aids in containing mess and simplifying cleanup.
Slip Stone:
A sharpening stone featuring rounded or tapered edges, employed for honing knives or tools with intricately shaped edges, particularly useful for sharpening carving gouges and V tools.
Soft Arkansas Stone:
A type of Arkansas Stone possessing a specific gravity ranging from 2.25 to 2.30. These stones are denser and finer compared to Washita Stones but less dense and coarser than Hard Arkansas, Hard Black Arkansas, or Hard Translucent Arkansas stones. Soft Arkansas Stones are akin to 600-800 grit stones. They exhibit various colors such as gray, white, pink, or black, or a blend of these hues, with color not impacting the grading, only specific gravity.
Spessartite:
A type of garnet comprising manganese aluminum silicate, named after a region in Bavaria where it's discovered. It serves as the abrasive mineral in Belgian Blue Whetstones and Coticule Whetstones. Also known as Spessertine.
Stainless Steel:
A variety of steel alloys known for their resistance to corrosion because of the significant chromium content they possess. Utilized in crafting cutting blades, particularly in applications where rust resistance is vital, such as kitchen knives.
Steel:
The primary iron alloy frequently employed in the production of edged cutting tools. Historically denoted a metal rod crafted for honing or realigning the edge of knives. These rods may feature file-like grooves or a smooth surface. In modern contexts, "steel" encompasses any rod-shaped sharpening implement with a handle, including diamond and ceramic variants. The act of sharpening using a sharpening steel.
Stone:
A diminutive fragment of rock resembling a pebble. An abrasive block-shaped product utilized for honing knives, tools, etc.
Strop:
A strop is a belt or strap made of leather or fabric. You fix one end to something steady and hold the other end by hand to make it tight. Razor Strops can be used with or without a special polish on them. They're mainly used to get straight razors ready for shaving, which is why they're called Razor Strops.
Super Steel:
Refers to a range of steel types known for their excellent edge retention. These steels often possess high abrasion resistance or hardness. However, there's no widely agreed-upon definition for what qualifies as super steel, leading to varied usage of the term by manufacturers, knife vendors, and users. Blades identified as crafted from super steel may pose challenges during sharpening due to their elevated abrasion resistance.
Surgical Steel:
Denotes various grades of stainless steel frequently employed in crafting medical instruments. The definition of surgical steel lacks universal consensus, allowing manufacturers to use the term according to their discretion.
Swarf:
Fine metal filings or shavings that are removed by a cutting tool, sharpening stone, or abrasive.
T
Temper:
To make steel hard, you heat it and then cool it in a special way. This makes the steel tough. But if you heat it too much when sharpening, it can lose this toughness.
Tool Steel:
Many kinds of steel are used for making tools because they are hard, resist abrasion, and hold their edge well, which makes them great for tools.
Tool Sharpening Guide:
A jig used to hold a tool or knife steady during sharpening, increasing efficiency by ensuring a consistent bevel angle.
Tungsten Carbide:
Tungsten and carbon mix to form tungsten carbide, which is used for making cutting tools because it's very hard and can withstand high temperatures. When you sharpen tungsten carbide tools, you need really tough abrasives like diamond or cubic boron nitride. It's sometimes called Carbide for short.
W
Water Stone:
A type of stone, either natural or man-made, used to sharpen knives and tools. Water is used to wash away the metal shavings. Water stones wear down unevenly and need to be flattened regularly. They come in different levels of coarseness, from 122.5 micron/120 mesh to .49 micron/30,000 mesh.
Whet:
To sharpen by abrading or grinding. Now a somewhat archaic word.
Whetstone:
An abrasive product in block form used for sharpening knives, tools, etc. Often confused with Water Stone because of the phonetic similarity between "wet" - soaked with water, and "whet" - to sharpen. All sharpening stones are whetstones. Only some whetstones are water stones.
Z
Zirconium Dioxide:
A type of material made up of one zirconium and two oxygen atoms, also called zirconia or zirconium oxide. It's a really hard ceramic used for making knife blades. Zirconia is also used as a tough abrasive in strong sanding belts.
