Carbide Grade Selection 331

abrasive wear

The process of an object losing material over time due to friction caused by rubbing against another object. Abrasive wear always occurs during metal cutting operations but it can be controlled through using coated carbide tools.

adhesion

The measure of bond strength between a binder and the material it binds. Cobalt is the most common binder used in carbide tools because it provides excellent adhesion.

alloys

A metal with purposefully added elements to enhance its mechanical and physical properties. Alloys can also refer to elements added to metal.

alphanumeric

Containing both letters and numbers. Both ANSI and the ISO use alphanumeric symbols to categorize carbide cutting tools.

alumina

A common coating material used on carbide cutting tools that provides excellent thermal and chemical protection for the substrate. Alumina, also known as aluminum oxide, can only be deposited on a cutting tool using CVD processes.

aluminum oxide

Al₂O₃. A common coating material used on carbide cutting tools that provides excellent thermal and chemical protection for the substrate. Aluminum oxide, also known as alumina, can only be deposited on a cutting tool using CVD processes.

American National Standards Institute

ANSI. A private, non-profit organization that administers and coordinates voluntary standards and systems. The American National Standards Institute provides a classification system for carbide cutting tools describing them by using the letter "C" followed by a number usually in the range 1 through 8.

ANSI

American National Standards Institute. A private, non-profit organization that administers and coordinates voluntary standards and systems. ANSI provides a classification system for carbide cutting tools describing them by using the letter "C" followed by a number usually in the range 1 through 8.

binder

A material that holds the particles of a sintered material together. Cobalt is the most common binder used in creating carbide cutting tools.

brittle

A material's resistance to being stretched, formed, or drawn. Brittle materials fracture easily and brittleness often increases with hardness levels.

carbide

A common cutting tool material created by combining carbon with a hard metal, such as titanium or tungsten. Carbide tools are the most commonly used tools in the metal cutting industry.

carbide substrate

The base material that makes up the majority of a coated carbide cutting tool. A carbide substrate is a carbide cutting tool without a coating.

carbide tools

A cutting tool with excellent toughness, hardness, and wear resistance, made by suspending one or more carbide compounds in a metallic binder. Carbide tools, also known as cemented carbides or sintered carbides, are made through compressing carbide with a binder, then heating the part to create a finished cutting tool.

cast irons

An alloy of iron, carbon, and silicon that contains at least 2.0% carbon. Cast irons can be machined using carbide grades rated C1 to C4 by ANSI classification and by carbide grades rated K or M by ISO classification.

cemented carbides

A cutting tool with excellent toughness, hardness, and wear resistance, made by suspending one or more carbide compounds in a metallic binder. Cemented carbides, also known as carbide tools or sintered carbides, are made through compressing carbide with a binder, then heating the part to create a finished cutting tool.

ceramic

A hard, brittle material that can withstand high temperatures. Ceramic cutting tools lack toughness and require high cutting speeds and rigid machinery.

chemical vapor deposition

CVD. A process that uses chemical reactions at high temperatures to coat a cutting tool with thick, well-bonded coating layers. Chemical vapor deposition is best suited for coating tools that will be used for high-speed cutting applications.

chemical wear

Tool degradation due to interactions between two substances that change the make up of the substances. Chemical wear of tools can be controlled by using coated carbide tools.

chromium

A shiny, hard, gray metal that increases corrosion resistance in metals. Chromium is used as a binder in carbide cutting tools when superior corrosion resistance is needed.

cobalt

A hard, gray, brittle metal that is highly magnetic. Cobalt is the most common binder used in carbide cutting tools because of its superior coating and adhesion characteristics.

composites

A material made by combining at least two other materials where the combined materials remain separate and distinct. Composites have different physical and chemical properties from the individual materials they combine.

compressed

Material that is pushed or pressed to force it together. Powdered carbide particles and binder are compressed to form a solid cutting tool.

condense

The process of changing from a gas or vapor to a liquid or solid. Gaseous coating materials condense on the substrate to form a layer of coating.

continuous cuts

A type of cut during which the cutting tool is in continuous contact with the workpiece. Continuous cuts should be made with carbide or ceramic cutting tools.

crater

A depression that forms on the face of a cutting tool above the cutting edge during machining. A crater is typically caused by diffusion as the chip works its way up the face of the tool and can cause cutting-edge failure.

C-system

The ANSI carbide insert classification standard. The C-system uses the letter "C" followed by a number, usually ranging from 1 to 8, to describe carbide tool grades.

cubic boron nitride

CBN. A cutting tool material offering a hardness that is second only to diamond. Cubic boron nitride tools are efficient but are expensive.

cutting edge

The part of the cutting tool that engages the workpiece during the machining operation. The type of cutting edge, which include honed, unhoned, or chamfered, is an important factor in selecting the carbide tool grade for a cutting procedure.

cutting edges

The part of the cutting tool that engages the workpiece during the machining operation. The type of cutting edge, which include honed, unhoned, or chamfered, is an important factor in selecting the carbide tool grade for a cutting procedure.

cutting variables

An adjustable component of a metal cutting operation. Cutting variables include tool geometry, tool material, and feed and speed.

die

A manufacturing tool that shapes parts through the compression of an upper and lower punch. A die is used to compress powered metal into a solid, though brittle, part in the powdered metallurgy process.

discontinuous chips

A chip that easily fractures from the workpiece into a small, separate piece. Brittle materials tend to create discontinuous chips.

drills

A tool that creates holes. Drills can be made from cemented carbides.

electric arcs

An electric charge that moves between two objects to generate heat. Electric arcs can be used to vaporize coating material in physical vapor deposition (PVD) processes.

electron beam

A narrow stream of electrons that creates focused thermal energy. Electron beams are used in some physical vapor deposition (PVD) processes to evaporate the coating material.

evaporated

Turned from a solid or liquid into a gas. Coating material is evaporated so it can condense on a substrate in physical vapor deposition (PVD).

feed

The rate at which the cutting tool and/or workpiece move in relationship to one another. Feed is often measured in inches per minute (ipm) or millimeters per minute (mm/min).

ferrous

A metal in which iron is the main ingredient. Ferrous metals include steel and cast iron and are the most commonly used commercial metals.

finishing

A final metal cutting pass that emphasizes tight tolerances and smooth surface finish. Harder materials, like carbides rated C4 by the ANSI classification system, are used during finishing.

flank wear

Tool wear resulting in the gradual wearing away of the cutting edge and flank due to abrasion. Flank wear develops more quickly when using titanium carbide (TiC) cutting tools.

fracture

The catastrophic failure of a cutting tool due to the sudden separation of a large piece of the tool. Fracture is a concern when using carbide cutting tools coated with chemical vapor deposition (CVD).

gaseous

A substance that has the characteristics of a gas. Gaseous substances expand freely to fill any available space.

grade

A letter and/or number designation that indicates the specific chemical and material composition for a particular cemented carbide tool or that indicates how that tool should be used. Grade is highly variable between manufacturers and any broad classification system can only be used as a general guideline.

gradient technology

The concentration of different components within different regions of a sintered material. Gradient technology allows toughness and hardness to be concentrated in areas of the tool where they are needed most.

H grades

An ISO category that includes carbide cutting tools best suited for machining hardened metals. Carbide tools with H grades are usually marked with gray on manufacturer specifications.

hardened

A metal that has been subjected to a manufacturing process, such as heating and quenching, to improve its hardness. Hardened metals should be machined with H-grade carbide cutting tools.

hardness

A material's ability to resist penetration, indentation, or scratching. Hard materials also tend to be very resistant to wear.

high-speed

A machining process that takes place at a fast speed or feed rate. High-speed applications usually benefit from the use of carbide tools with added TaC, which improves tool performance at the high temperatures caused by rapid workpiece movement.

high-speed steel

HSS. A metal used to create cutting tools in order to machine other metals. High-speed steel is tougher than carbide but offers less hardness and wear resistance.

high-temperature alloys

A group of metals based on iron, cobalt, or nickel with alloying elements to give them superior heat resistance. High-temperature alloys should be machined with S-grade carbide cutting tools.

insert number

A long series of numbers and/or letters used to describe a cutting tool insert. Insert number often refers to the ANSI or ISO insert identification number, which is separate from the ANSI or ISO grade classification.

inserts

A removable, geometric cutting bit that has multiple cutting edges. Inserts are classified according by grades and insert numbers.

International Organization for Standardization

ISO. An international organization that establishes standards and guidelines for various products and processes. The International Organization for Standards provides a classification system for carbide cutting tools, describing them by using letters including "P", "M", and "K" followed by a number.

interrupted cuts

A type of cut during which one or more edges of a cutting tool are in only intermittent contact with the workpiece. Interrupted cuts should be made with carbide or HSS cutting tools.

ions

A positively or negatively charged atom. In physical vapor deposition (PVD), positively charged ions in the vaporized coating are attracted to negatively charged ions in the tool substrate.

ISO

The International Organization for Standardization. An international organization that establishes standards and guidelines for various products and processes. The ISO provides a classification system for carbide cutting tools, describing them by using letters including "P", "M", and "K" followed by a number.

K grades

An ISO category that includes carbide cutting tools best suited for machining cast iron. Carbide tools with K grades are usually marked with red on manufacturer specifications.

low-speed

A machining process that takes place at a slow speed or feed rate. Low-speed applications usually benefit from the use of carbide tools coated through physical vapor deposition (PVD).

M grades

An ISO category that includes carbide cutting tools best suited for machining stainless steels. Carbide tools with M grades are usually marked with yellow on manufacturer specifications.

mechanical arm

An automated device that can manipulate objects. In manufacturing, a mechanical arm is used to pick up and move parts during various stages of the production process.

N grades

An ISO category that includes carbide cutting tools best suited for machining nonferrous metals and alloys. Carbide tools with N grades are usually marked with green on manufacturer specifications.

nickel

A hard, ductile, silvery-white metal. Nickel is sometimes used as a binder when creating carbide cutting tools when corrosion and oxidation are particular concerns.

nonferrous

A metal that does not contain a significant amount of iron. The most commonly used nonferrous metals are aluminum and copper.

operators

A person trained to run a specific machine. Operators are responsible for helping ensure that a machining process runs properly, efficiently, and safely.

P grades

An ISO category that includes carbide cutting tools best suited for machining a variety of steels. Carbide tools with P grades are usually marked with blue on manufacturer specifications.

physical vapor deposition

PVD. A process that deposits a thin, even layer of coating on the surface of a tool using ions to attract evaporated coating material. Physical vapor deposition is best suited for coating tools that will be used for low-speed cutting applications.

plasma-assisted CVD

PaCVD. A chemical vapor deposition process that uses plasma to assist with vaporization and the reaction of the chemical vapor. Plasma-assisted chemical vapor deposition can be performed at a much lower temperature than traditional chemical vapor deposition.

powdered metallurgy

The process of creating parts through compressing and heating granulated metal. Powdered metallurgy is used to create parts without metal removal processes and is often used to make cutting tools.

precipitates

To separate as either a solid from a liquid solution or a liquid from a gaseous solution. A carbide that dissolves then precipitates out of the metal binder helps to ensure uniform composition of the finished cutting tool.

punches

A moving machine component used to apply pressure to a part. In powdered metallurgy, punches compress the powdered material into a solid, but brittle, part.

roughing

A cutting pass that emphasizes high material removal rate over the quality of surface finish or accuracy. Tougher materials, like carbides rated C1 by the ANSI classification system, are used during roughing.

S grades

An ISO category that includes carbide cutting tools best suited for machining high-temperature alloys. Carbide tools with S grades are usually marked with orange on manufacturer specifications.

shoe

A manufacturing component that funnels powdered carbide and cobalt into a die. The shoe may also push the compressed carbide part onto a conveyor belt so the part can be sintered.

sintered

A compressed part that has been heated to harden it and create the finished tool. Compressed carbide cutting tools must be sintered before they can be used in manufacturing.

sintered carbides

A cutting tool with excellent toughness, hardness, and wear resistance, made by suspending one or more carbide compounds in a metallic binder. Cemented carbides, also known as carbide tools or cemented carbides, are made through compressing carbide with a binder, then heating the part to create a finished cutting tool.

sintering

The heating of pressed powdered materials close to their melting point to create a finished product with improved hardness. Sintering creates materials with very uniform compositions.

speed

The rate at which the surface of the workpiece rotates past the cutting edge of a tool at the point of contact. Speed is often measured in revolutions per minute (rpm).

stainless steels

A type of steel that contains more than 11% chromium and exhibits excellent corrosion resistance. Stainless steels are usually machined using carbide grades rated P by ISO classification.

steel

A metal consisting of iron and carbon, often alloyed with other elements. Steel is the most common manufacturing metal.

stresses

A force that attempts to deform an object. Stresses are formed during chemical vapor deposition (CVD) processes and can lead to tool fracturing.

substrate

The material onto which a coating is applied. Substrate can refer to a carbide cutting tool when it is undergoing a coating process.

tantalum

A hard, blue-gray metal that is inert to most chemicals. Tantalum is used to create carbides for cutting tools when toughness is a particular concern.

tantalum carbide

TaC. A compound of tantalum and carbon. Tantalum carbide is used as an alloy with tungsten carbide to increase a cutting tool's resistance to thermal deformation.

titanium

A silver-gray, strong, lightweight metal known for its corrosion resistance and strength-to-weight ratio. Titanium is used when creating carbide particles for cutting tools because it resists certain types of chemical attacks.

titanium carbide

TiC. A compound of titanium and carbon that can be used as the basis for a cutting tool material, added to tungsten carbide for steel cutting grades, or used as a coating. Titanium carbide offers improved chemical stability and crater resistance.

titanium carbonitride

TiCN. A compound of titanium, carbon, and nitrogen often used as coating for carbide cutting tools. Titanium carbonitride offers good abrasive wear resistance and helps coating layers adhere to the substrate.

titanium nitride

TiN. A common coating material used on carbide cutting tools to reduce friction. Titanium nitride has a characteristic yellow or gold color that makes wear more visible.

tool geometry

The collective angles formed by the dimensions of a cutting tool that make a tool unique. Tool geometry is an important factor is carbide grade selection.

toughness

The ability of a material to absorb energy without breaking or fracturing. Tough cutting tools are able to withstand sudden stresses but are less hard.

tungsten

A dense, grayish-white metal with superior heat resistance. Tungsten is the most commonly used metal when making carbide particles for cutting tools because of its excellent wear resistance.

tungsten carbide

WC. A compound of tungsten and carbide that was used as the original carbide tool material. Tungsten carbide offers excellent hardness, but is generally mixed with other carbides to avoid cratering when machining steel.

unalloyed

A metal containing no significant addition of another metal. Unalloyed carbide cutting tools include ISO grades K, N, S, and H and ANSI grades C1 through C4.

vacuum chamber

An enclosed space from which all air and gas is removed. A vacuum chamber is used in both chemical vapor deposition (CVD) and physical vapor deposition (PVD).

wear

The erosion of material as a result of friction, chemical reaction, or other degrading processes. Typical tool wear includes flank, crater, and notch wear.

wetting

The behavior of a liquid when it contacts a solid surface. Liquids with good wetting ability, such as liquid cobalt, spread out evenly over a solid surface area.

workpiece

A part that is subjected to a manufacturing process such as metal cutting or welding. Any metal being cut is referred to as a workpiece.

zirconium oxide

ZrO₂. A white crystalline compound of oxygen and zirconium that is used as a coating for carbide cutting tools. Zirconium oxide resists oxidation and corrosion at high temperatures.