ANSI Insert Selection 341

35° diamond inserts

An indexable cutting tool with four equal sides that create two 35° angles at the cutting edges. A 35° diamond insert, also known as a Type-V insert, has the lowest cutting edge strength but creates the most precise and intricate cuts.

55° diamond inserts

An indexable cutting tool with four equal sides that create two 55° angles at the cutting edges. A 55° diamond insert, also known as a Type-D insert, has low cutting edge strength but is essential for precise cutting operations, such as tracing.

80° diamond inserts

An indexable cutting tool that has four equal sides that create four 80° angles. A 80° diamond insert, also known as a Type-C insert, is used for a wide range of operations, such as facing and turning, but is not as precise as diamond inserts with smaller included angles.

alphanumeric

Containing both letters and numbers. Alphanumeric labels are used by both ANSI and ISO to categorize carbide cutting tools.

American National Standards Institute

ANSI. A private, nonprofit organization that administers and coordinates voluntary standards and systems. The American National Standards Institute provides a classification system for carbide cutting tools using an alphanumeric label that details characteristics such as size, shape, and tolerance.

ANSI

American National Standards Institute. A private, nonprofit organization that administers and coordinates voluntary standards and systems. ANSI provides a classification system for carbide cutting tools using an alphanumeric label that details characteristics such as size, shape, and tolerance.

B212.4-1995 standard

The specifications created by ANSI to describe an indexable cutting insert using an alphanumeric label. The B212.4-1995 standard includes information about how to represent insert size, shape, and thickness, among other specifications, in the insert identification number.

carbide cutting tools

A machining tool with excellent toughness, hardness, and wear resistance. Carbide cutting tools are made through compressing carbide with a binder, then heating the part to create a finished cutting tool.

cast iron

An alloy of iron, carbon, and silicon that contains at least 2.0% carbon. Cast iron can be machined using round inserts because it is brittle and creates discontinuous chips.

chamfers

A beveled surface that eliminates a 90° sharp corner on the cutting edge. Chamfers are often created at 45° angles.

chipbreakers

A feature or device designed to prevent chips from forming into long pieces. Chipbreakers are either molded features on the surface of the cutting insert or wafers clamped above the insert in the toolholder.

chipbreakers

An insert feature designed to prevent chips from forming into long pieces. Chipbreakers are either molded features on the surface of the cutting insert or a wafer clamped above the insert in the toolholder.

clearance angle

An angle formed by the end flank of the insert and the workpiece surface. Clearance angle helps determine the strength of the cutting edge and the quality of part finish.

clearance angle

An angle formed by the end flank of the insert and the workpiece surface. Required clearance angle varies depending on the specific insert and application.

contours

A curved surface or dimension cut into a workpiece. Contours are often created using a triangle insert.

countersinks

An interior beveled surface that provides room for the head of a screw. Countersinks in inserts allow screws to sit flush with the insert surface.

cutoff

A shearing operation that performs a single cut in order to separate a piece of metal from the original stock. Cutoff operations are often done with tools featuring a rectangle or parallelogram cutting insert.

cutting direction

The angle from which a cutting tool must approach the workpiece, based on the shape and design of the insert. Cutting tool direction can be described as right-handed, left-handed, or neutral.

cutting edge

The leading face of a cutting tool that is in direct contact with the workpiece. The cutting edge performs the actual metal removal during a cutting operation.

cutting fluid

Any fluid used to cool, lubricate, and clear chips during metal cutting. A cutting fluid can be oil- or water-based liquid, gas, or paste.

cutting forces

The various stresses involved in a machining process. Cutting forces are determined by a combination of speed and feed rate, tool angle, workpiece material, and other factors.

cutting inserts

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

cutting point

The corner of the insert where the cutting edges meet that is in contact with and cuts the workpiece. Cutting point shape determines factors such as the strength of the insert, surface finish quality, and effective depth of cut.

cutting point

The edge of the insert that performs the actual cut or the corner of the cutting edge that is in contact with the workpiece. The shape of the cutting point determines factors such as the strength of the insert, finish quality, and effective depth of cut.

depth of cut

The distance between the bottom of the cut and the uncut surface of the workpiece. Depth of cut determines how much material is removed with a single pass of the tool.

diameter

A line that extends from one edge of a circle to the opposite edge while intersecting the center. The diameter measurement is used to describe inscribed circles for carbide inserts under the ANSI system.

discontinuous chip

A chip that easily fractures from the workpiece into small, separate pieces. A discontinuous chip is usually formed when machining brittle materials such as cast iron.

end cutting edge angle

The angle formed by the line of the side flank and the line of the surface with which the tool is engaged. End cutting edge angle affects cutting edge strength; the greater the end cutting edge angle, the weaker the cutting edge.

facet

A small, flat surface next to the cutting point. A facet affects the amount of insert contact with the workpiece behind the action of the cutting edge.

facet angle

The angle created between the primary cutting edge and the workpiece in the direction of the feed. Facet angle and facet clearance are described by two letters if the insert has a facet.

facet angle

The slope of the flat edge directly adjacent to the cutting edge. A large facet angle decreases insert strength but increases its finishing ability.

facet clearance

The angle created between the facet and the workpiece. The smaller the face clearance, the closer the facet is to the workpiece.

facet clearance

The angle created between the facet and the workpiece. The smaller the facet clearance, the closer the facet is to the workpiece.

facing

A cutting operation where a tool is fed across the end of a cylindrical workpiece to create a flat surface and shorten its length. Facing is often done with diamond cutting inserts.

feed

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

flank

A flat surface of a single-point tool that is adjacent to the face of the tool. The side flank faces the direction that the tool is fed into the workpiece, and the end flank passes over the newly machined surface.

flush

In line with another surface. Countersinks allow screws to sit flush with the face of a cutting tool.

grade

A letter and/or number designation that indicates the specific chemical and material composition for a particular carbide cutting tool or 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.

grooving

A machining operation performed on the lathe that cuts a narrow channel into a rotating cylindrical workpiece. Grooving is often done with rectangle or parallelogram inserts.

ground

Machined with an abrasive to achieve accurate dimensions. Inserts that have been ground on all faces have tighter tolerances than those ground on just two faces.

hexagon inserts

An indexable cutting insert with six equal sides that form 120° angles. Hexagon inserts, also known as Type-H inserts, have good cutting edge strength but can only be used at positive lead angles, which can limit their use.

high-carbon steel

A plain carbon steel that contains more than 0.45% carbon. High-carbon steel is extremely strong and hard, and it can require special insert preparation, such as chamfers, when being cut.

honed

An intentionally blunted or rounded-off cutting edge. Honed edges increase strength.

IC

Inscribed circle. A circle that fits exactly within the boundaries of another shape. An inscribed circle is used to measure the overall shape of a carbide insert.

included angle

An angle formed by the two sides of the insert that merge at the cutting point. Included angles affect insert strength.

indexable

A cutting tool with multiple cutting edges that can be rotated into place. Indexable inserts can be turned to expose a new cutting edge when one cutting edge wears out.

inscribed circle

IC. A circle that fits exactly within the boundaries of another shape. An inscribed circle is used to measure the overall size of a carbide insert.

inscribed circle

IC. A circle that fits exactly within the boundaries of another shape. The inscribed circle of an insert touches all cutting edges and is an ANSI indicator for insert size.

insert number

A series of numbers and/or letters used to describe a cutting tool insert. The insert number, also known as a part number or product number, usually refers to the ANSI insert identification number, but it can also refer to the ISO insert identification number.

insert style

The description of the features present on an indexable cutting insert. Insert style, also known as insert type, is defined by the presence or absence of features such as holes, countersinks, and chipbreakers.

insert type

The classification of a carbide cutting tool related to the presence or absence of chipbreakers, countersinks, and holes. Insert type is described by the insert number of a tool.

insert type

The description of the features present on an indexable carbide cutting insert. Insert type, also known as insert style, is defined by the presence or absence of features such as holes, countersinks, and chipbreakers.

International Organization for Standardization

ISO. An international organization that establishes standards and guidelines for various products and processes. The International Organization for Standardization provides an alphanumeric labeling system for carbide cutting inserts to describe and organize their important characteristics.

ISO

International Organization for Standardization. An international organization that establishes standards and guidelines for various products and processes. The ISO provides an alphanumeric labeling system for carbide cutting inserts to describe and organize their important characteristics.

lathe

A machine tool that is used to produce a range of cylindrical workpieces. On a basic lathe, the part is rotated in a spindle while a single-point tool is guided along its exterior to shape the part or into the workpiece to create grooves or threads.

lead angle

The angle formed by the side flank of the tool and a line perpendicular to the workpiece centerline, if viewing a cutting tool from above. A positive lead angle moves the side flank into the cut, and a negative lead angle moves the side flank out of the cut.

left-handed

A tool that has its major cutting edge on the left side of the insert when viewed from the end of the workpiece looking toward the cutting tool. Left-handed tools are indicated by an "L" as the ninth character in the ANSI insert number system.

light machining

The machining of easily cut metals at low speeds and light feeds. Light machining can be performed with inserts that have chipbreakers on both sides.

low-carbon steel

A plain carbon steel that contains less than 0.30% carbon. Low-carbon steels are ductile and prone to forming long, stringy chips.

mechanical chipbreakers

A small wafer clamped onto the toolholder with the cutting insert to prevent long chips from forming. Mechanical chipbreakers are helpful when performing operations that remove large amounts of metal but make indexing a cutting tool more challenging.

medium machining

Machining metals at moderate speeds and feeds. Medium machining can be performed with inserts that have chipbreakers on both sides.

metal cutting

A machining process that uses a tool to remove metal from a workpiece. Metal cutting processes include drilling, turning, and milling.

milling

A machining operation that uses a multi-point horizontal or vertical cutter to remove metal from the surface of the workpiece. Milling is often performed with cutting tools that have parallelogram cutting inserts.

milling cutters

A multi-point cutting tool that has teeth around its cutting edge. Milling cutters often have rectangle or parallelogram inserts as their cutting teeth.

multi-point

A machining tool that has two or more cutting edges. Multi-point cutting tools are used in milling and broaching.

neutral

A tool that can be used to cut from the left, the right, or from a position directly above the centerline of the workpiece. Neutral tools are indicated by an "N" as the ninth character in the ANSI insert number system.

neutral

Taking no side. A tool with a neutral cutting direction can be used to cut from both the left and the right side.

nomenclature

A specific naming or numbering system used to logically categorize items. Nomenclature describes the use of number and letter designations to categorize and classify the properties of a tool.

nominal

A stated measurement that may not correlate exactly with a physical part. Nominal measurements for an insert indicate size specified in the blueprint, which will differ from the size of the actual part.

nose radius

The degree of roundness between the two cutting edges of a tool. Nose radius is described by the insert number and influences factors such as surface finish and insert strength.

nose radius

The degree of roundness between two cutting edges of a tool. The greater the nose radius, the greater the roundness of the tip, which leads to greater metal removal rate but also increased tool chatter.

nose radius

The degree of roundness between two cutting edges of a tool. The nose radius is described by the insert number and influences factors such as surface finish and insert strength.

octagon inserts

An indexable insert with eight equal sides that form 135° angles. Octagon inserts, also known as Type-O inserts, have good cutting edge strength but can only be used in limited applications.

operators

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

parallelogram inserts

An indexable cutting insert with two sets of opposite sides that are equal and parallel. Parallelogram inserts are often used in milling cutters and common versions come with included angles measuring 85°, 82°, and 55 degrees.

part number

A series of numbers and/or letters used to describe a cutting tool insert. The part number, also known as an insert number or product number, usually refers to the ANSI insert identification number, but it can also refer to the ISO insert identification number.

pentagon inserts

An indexable cutting insert that has five equal sides that form 108° angles. Pentagon inserts, also known as Type-P inserts, have excellent cutting edge strength but are prone to tool chatter.

perpendicular

An intersection of two lines or objects at a right angle. Perpendicular lines are used to determine several aspects of tool geometry, including rake angles.

polished

Ground to have an exceptionally smooth surface quality. A polished edge is machined to have a surface that is smooth up to a 4 microinch (µin), or 0.10 micrometer (µm), magnification.

precision inserts

An indexable carbide cutting tool primarily used for finishing operations. Precision inserts have very tight tolerances.

product number

A series of numbers and/or letters used to describe a cutting tool insert. The product number, also known as an insert number or part number, usually refers to the ANSI insert identification number, but it can also refer to the ISO insert identification number.

profiling

The process of machining tapered, contoured, or curved surfaces. Profiling requires the use of cutting inserts with smaller included angles.

rake

The incline of the face of the cutting tool in relation to the workpiece. The rake controls the degree of cutting forces and cutting edge strength.

rake angle

An angle describing the tilt of the tool face away from or toward the surface of the workpiece. A rake angle can be negative or positive.

rectangle inserts

An indexable cutting insert featuring opposite sides that are equal and parallel and come together at 90° angles. Rectangle inserts, also known as Type-L inserts, are often used in milling cutters.

right-handed

A tool that has its major cutting edge on the right side of the insert when viewed from the end of the workpiece looking toward the cutting tool. Right-handed tools are indicated by an "R" as the ninth character in the ANSI insert number system.

roughing

A cutting pass that emphasizes high material removal rate over the quality of surface finish or accuracy. Roughing is often performed using inserts with less exact tolerances.

round inserts

A circular indexable cutting tool. Round inserts, also known as Type-R inserts, have the greatest edge strength but the highest risk of tool chatter.

screw

A threaded device used for fastening parts. A screw may be used to more securely hold a cutting insert with a countersink.

screw

A threaded device used for fastening parts. A screw may be used to more securely hold a cutting insert with a hole and a countersink.

service life

The length of time a cutting tool is expected to be operational before it must be replaced. A carbide cutting tool has a long service life.

severe machining

A machining operation occurring under very high pressures or temperatures. Severe machining often requires the use of inserts that have chipbreakers sintered into one side.

shoulders

An angled surface similar to a chamfer created by milling or turning. Shoulders are often created using a triangle cutting insert.

single-point

A cutting tool that has a single cutting edge. Single-point cutting tools are used in manufacturing applications such as turning.

sintered

A solid tool with specific features formed by pressing and heating powdered material. Chipbreakers are among the features that can be built into sintered cutting inserts.

speed

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

square inserts

An indexable cutting tool that has four equal sides that meet at 90° angles. Square inserts, also known as Type-S inserts, offer a good balance of edge strength and reduced risk of tool chatter.

square shoulders

A cut made in a cylindrical workpiece that leaves a narrow section of the workpiece connected to the larger piece at a series of 90° angles. Square shoulders can only be cut using inserts with smaller included angles such as diamond or triangular inserts.

steel

An alloy of iron and carbon containing less than 2.0% carbon. Steel machined at high speeds can form long chips that can damage metal cutting equipment.

strength

The ability of a material to resist forces that attempt to break or deform it. Inserts with good strength can operate at higher feed rates and withstand tool wear.

thickness

The measurement of the wideness of an insert when viewing it from the side. Thickness is described by the cutting insert number.

threading

The process of cutting a spiraling groove into a cylindrical workpiece. Threading is often done with rectangle or parallelogram inserts.

tolerance

An unwanted but acceptable deviation from a given dimension defined by a blueprint. Tolerance of a carbide insert is one of the factors described by an insert number.

tool chatter

Vibrations of the cutting tool that cause surface imperfections on the workpiece. Tool chatter is more common when using inserts with larger included angles such as round inserts.

tool face

The flat surface on a carbide cutting insert facing away from the toolholder. Tool face indicates the large surface right above the cutting edge.

tool fracture

The breaking of a tool into two or more pieces as a result of stress. Tool fracture is common in cutting inserts that have low edge strength, such as 55° parallelogram or 35° diamond inserts.

toolholder

A device used to hold a cutting tool in place during machining. A toolholder is designed to be paired with a few specific insert types.

tracing

A cutting operation that involves making very shallow cuts into a workpiece. Tracing is done with precise cutting inserts such as 35° diamond inserts.

triangle inserts

A cutting insert with three equal sides that create three equal angles. Triangle inserts, also known as Type-T inserts, are considered the best general-purpose inserts.

trigon inserts

A triangular cutting insert with 80° included angles. Trigon inserts, also known as Type-W inserts, are less versatile than triangle inserts but offer better cutting edge strength.

turning

A machining operation where a single-point cutting tool is guided along the length of a rotating cylindrical workpiece. Turning is often performed with trigon, diamond, or triangle cutting inserts.

Type A

A parallelogram cutting insert with 85° included angles. Type-A inserts have the strongest cutting edges of all parallelogram inserts.

Type B

A parallelogram cutting insert with 82° included angles. Type-B inserts have the second strongest cutting edges of all parallelogram inserts.

Type C

An indexable cutting tool that has four equal sides that create four 80° angles. Type-C inserts, also known as 80° diamond inserts, are used for a wide range of operations, such as facing and turning, but are not as precise as diamonds with smaller included angles.

Type D

An indexable cutting tool with four equal sides that create two 55° angles at the cutting edges. Type-D cutting inserts, also known as 55° diamond inserts, have low cutting edge strength but are essential for precise cutting operations such as tracing.

Type H

An indexable cutting insert with six equal sides that form 120° angles. Type-H inserts, also known as hexagon inserts, have good cutting edge strength but can only be used at positive lead angles, which can limit their use.

Type K

A parallelogram cutting insert with 55° included angles. Type-K inserts have the second weakest cutting edges of all inserts but are very precise.

Type L

An indexable cutting insert featuring opposite sides that are equal and parallel and come together at 90° angles. Type-L inserts, also known as rectangle inserts, are often used in milling cutters.

Type O

An indexable insert with eight equal sides that form 135° angles. Type-O inserts, also known as octagon inserts, have good cutting edge strength but can only be used in limited applications.

Type P

An indexable cutting insert that has five equal sides that form 108° angles. Type-P inserts, also known as pentagon inserts, have excellent cutting edge strength but are prone to tool chatter.

Type R

A circular indexable cutting tool. Type-R inserts, also known as round inserts, have the greatest edge strength but the highest risk of tool chatter.

Type S

An indexable cutting tool that has four equal sides that meet at 90° angles. Type-S inserts, also known as square inserts, offer a good balance of edge strength and reduced risk of tool chatter.

Type T

A cutting insert with three equal sides that create three equal angles. Type-T inserts, also known as triangle inserts, are considered the most versatile of all cutting inserts.

Type V

An indexable cutting tool with four equal sides that create two 35° angles at the cutting edges. Type-V inserts, also known as 35° diamond inserts, have the lowest cutting edge strength but create the most precise and intricate cuts.

Type W

A triangular cutting insert with 80° included angles. Type-W inserts, also known as trigon inserts, are less versatile than triangle inserts but offer better cutting edge strength.

utility inserts

An indexable carbide cutting tool primarily used for roughing operations. Utility inserts generally have looser tolerances than precision inserts.

wear

The erosion of material as a result of friction. Wear can be prevented or reduced by using cutting inserts with good edge strength.

wipers

A specialized triangular cutting point geometry. Wipers can improve surface finish, extend tool service life, and increase cutting efficiency.

workpiece

A part that is subjected to a manufacturing process such as metal cutting or welding. A workpiece is any metal that is cut to create a finished product.