An Overview of Milling Cutter Types: A Comprehensive Guide to Product Classification

Milling cutter is a rotating cutting tool used for milling operations, which has one or more teeth. During operation, the teeth sequentially and intermittently remove the material from the workpiece. Milling cutters are primarily used for machining flat surfaces, steps, grooves, contour surfaces, and cutting off workpieces on milling machines.

Cylindrical Milling Cutter:

Used for machining flat surfaces on horizontal milling machines. The teeth are distributed along the circumference of the milling cutter and can be classified into straight teeth and helical teeth. They can also be classified into coarse teeth and fine teeth based on the number of teeth. Helical coarse teeth milling cutters have fewer teeth, higher tooth strength, larger chip space, and are suitable for rough machining. Fine teeth milling cutters are suitable for precision machining.

Face Milling Cutter:

Also known as a disc milling cutter, it is used for machining flat surfaces, end faces, and circumferences on vertical milling machines, end milling machines, or gantry milling machines.

It has teeth on the end face and circumference, and can be classified into coarse teeth and fine teeth. There are three types of structures: integral type, insert type, and indexable type.

End Mill:

Used for machining grooves and step surfaces, etc. The teeth are located on the circumference and end face of the cutter, and axial feeding is not allowed during operation. When there is a peripheral tooth passing through the center of the end mill, it can be fed axially.

Three-edge Milling Cutter:

Used for machining various grooves and step surfaces. It has teeth on both side faces and the circumference.

Angle Milling Cutter:

Used for milling grooves at a certain angle. There are single-angle and double-angle milling cutters.

Saw Blade Milling Cutter:

Used for machining deep grooves and cutting workpieces. It has more teeth on the circumference. To reduce friction during milling, there is a secondary relief angle of 15′~1° on both sides of the teeth. In addition, there are keyway milling cutters, dovetail slot milling cutters, T-slot milling cutters, and various form milling cutters.

T-slot Milling Cutter: Used to mill T-slots.

Product Structures:

Solid Type: The cutter body and teeth are made as a single piece.
Integral Welded Teeth Type: The teeth are made of hard alloy or other wear-resistant cutting tool materials and welded to the cutter body.
Insert Type: The teeth are fastened to the cutter body by mechanical clamping. The replaceable teeth can be either integral tool material heads or welded tool material heads. When the tool heads are ground on the cutter body, it is called in-situ grinding type; when the tool heads are individually ground on a fixture, it is called off-site grinding type.
Indexable Type: This structure is widely used in face milling cutters, end mills, three-edge milling cutters, etc.

Milling is a common metalworking method used to remove material from a workpiece by the rotational motion of a cutting tool, in order to obtain the desired shape and size of the part. When optimizing milling performance, the milling cutter is another important factor. It is advantageous to have multiple cutting edges participating in the cutting process, but having too many cutting edges participating simultaneously can be a disadvantage. The required power and the number of participating cutting edges are related to the chip formation process, cutting edge load, and machining results. The position of the milling cutter relative to the workpiece plays an important role.

In face milling, using a milling cutter that is approximately 30% wider than the cutting width and positioning the milling cutter close to the center of the workpiece results in minimal variation in chip thickness. To ensure a sufficiently high average chip thickness/feed per tooth, the number of teeth on the milling cutter must be determined correctly for the process. The tooth pitch of the milling cutter is the distance between the effective cutting edges. Based on this value, the milling cutter can be classified into three types: close pitch milling cutters, coarse pitch milling cutters, and extra-close pitch milling cutters.

The chip thickness in milling is also related to the primary clearance angle of the face milling cutter, which is the angle between the main cutting edge of the tool and the workpiece surface. It mainly includes 45-degree, 90-degree, and round-shaped inserts. The change in cutting force direction varies significantly with different primary clearance angles. A milling cutter with a 90-degree primary clearance angle mainly generates radial forces acting in the feed direction, which means that the machined surface will not bear excessive pressure and is more reliable for milling structurally weak workpieces.

A milling cutter with a 45-degree primary clearance angle has approximately equal radial cutting forces and axial cutting forces, resulting in a more balanced pressure distribution. It also requires lower power from the machine tool and is particularly suitable for milling short chips of brittle materials.

A round-shaped insert milling cutter means that the primary clearance angle continuously changes from 0 degrees to 90 degrees, depending on the cutting depth. This type of insert has high cutting edge strength, and due to the thinner chips produced along the long cutting edge, it is suitable for large feed rates. The direction of radial cutting force changes continuously along the cutting edge, and the pressure generated during the machining process depends on the cutting depth. Modern insert geometries have made round-shaped inserts have smooth cutting effects, lower power requirements, and good stability. They are widely used in face milling and peripheral milling and are no longer just effective for rough milling.

Milling Methods:

There are two milling methods based on the relationship between the feed direction and the rotation direction of the milling cutter relative to the workpiece:

  1. Conventional Milling: In conventional milling, the rotation direction of the milling cutter is the same as the feed direction. The milling cutter engages the workpiece and cuts off the final chip.
  2. Climb Milling: In climb milling, the rotation direction of the milling cutter is opposite to the feed direction. The milling cutter must slide on the workpiece for a distance before starting the cutting, with zero cutting depth at the beginning and reaching the maximum cutting depth at the end.

The cutting forces have different directions in face milling with a three-edge milling cutter, certain peripheral milling or face milling operations. In face milling, the milling cutter is located just outside the workpiece, and the direction of the cutting force needs to be paid special attention to. In conventional milling, the cutting force pushes the workpiece towards the worktable, while in climb milling, the cutting force tends to lift the workpiece off the worktable.

Conventional milling is generally preferred as it provides better cutting performance. Climb milling is only considered when there are issues with backlash in the machine tool or when conventional milling cannot solve the problem.

In ideal conditions, the diameter of the milling cutter should be larger than the width of the workpiece, and the axis of the milling cutter should be slightly off the centerline of the workpiece. When the tool is positioned exactly at the cutting center, burrs are more likely to be generated. The direction of radial cutting force changes continuously during the entry and exit of the cutting edge, which can cause spindle vibration and damage, tool breakage, and result in a rough machined surface. By slightly offsetting the milling cutter from the center, the direction of the cutting force will not fluctuate, and the milling cutter will have a pre-loading effect. This can be compared to driving along the centerline of a road.

For each cutting edge of the milling cutter, the manner in which the cutting edge disengages from the workpiece during exit is important. The remaining material near the exit can reduce the clearance of the tool to some extent. When the chip separates from the workpiece, it creates an instantaneous tensile force along the front face of the tool, often resulting in burrs on the workpiece. This tensile force can pose a safety risk tothe operator and can also lead to poor surface finish. To address this issue, a technique called “trochoidal milling” or “adaptive milling” can be used. In trochoidal milling, the cutting tool follows a curved path instead of a straight line during the machining process. This helps in reducing the impact of the instantaneous tensile forces and leads to improved surface finish and reduced burr formation.

In summary, optimizing milling performance involves considering various factors such as the type of milling cutter, the number of teeth, the primary clearance angle, the milling method (conventional or climb milling), and the position of the milling cutter relative to the workpiece. Each of these factors can have a significant impact on cutting forces, chip formation, surface finish, and overall machining efficiency. By understanding and optimizing these factors, manufacturers can achieve better milling results and improve productivity in their machining operations.

Product Categories

Sharp tooth milling cutter

A narrow edge is ground on the flank surface to form a relief angle. Due to the reasonable cutting angle, its service life is long. The tooth back of the sharp tooth milling cutter has three forms: straight line, curve and broken line. Straight tooth flanks are often used in finishing milling cutters with fine teeth. The teeth with curved and broken line tooth backs have better strength and can withstand heavier cutting loads, and are often used in coarse-tooth milling cutters.
Shovel tooth milling cutter
The back part is processed into the tooth back of the Archimedean spiral by shoveling (or shoveling). After the milling cutter is blunt, it only needs to be reground on the front side, which can keep the original tooth shape unchanged and is used to make gear milling cutters, etc. Various form milling cutters.

Milling cutter clamping

Most of the milling cutters used in machining centers use spring clamp sets and are in a cantilever state when used. During the milling process, sometimes the milling cutter may gradually protrude from the tool holder, or even completely fall off, causing the workpiece to be scrapped.

The reason is generally due to the gap between the inner hole of the tool holder and the outer diameter of the milling cutter shank. Oil film is caused by insufficient clamping force. Milling cutters are generally coated with anti-rust oil when they leave the factory. If non-water-soluble cutting oil is used during cutting, a mist-like oil film will also adhere to the inner hole of the tool holder. When there is an oil film on both the tool handle and the tool holder, the tool holder will be very It is difficult to clamp the tool holder firmly, and the milling cutter will become loose and lost during processing. Therefore, before clamping the milling cutter, the handle of the milling cutter and the inner hole of the tool holder should be cleaned with cleaning fluid and dried before clamping.
When the diameter of the milling cutter is large, even if the tool holder and tool holder are clean, a tool loss accident may still occur. In this case, a tool holder with a flattened notch and a corresponding side locking method should be used.
Another problem that may occur after the milling cutter is clamped is that the milling cutter breaks at the tool holder port during processing. The reason is usually that the tool holder has been used for too long and the tool holder port has been worn into a tapered shape. At this time, it should be Replace the tool holder with a new one.

Milling cutter vibration

Motion state of the milling cutter and the cutter tooth under vibration.

Figure 3 

Because there is a small gap between the milling cutter and the tool holder, the tool may vibrate during the machining process. Vibration will cause the cutting amount of the circumferential edge of the milling cutter to be uneven, and the cutting expansion amount will increase than the original value, affecting the machining accuracy and tool service life. However, when the width of the processed groove is too small, the tool can be vibrated purposefully to obtain the required groove width by increasing the cutting expansion amount. However, in this case, the maximum amplitude of the milling cutter should be below 0.02mm, otherwise it will not be possible. Perform stable cutting. The smaller the vibration of the milling cutter during normal machining, the better.
When tool vibration occurs, you should consider reducing the cutting speed and feed speed. If there is still large vibration after both have been reduced by 40%, you should consider reducing the amount of tool engagement.
If resonance occurs in the machining system, the reason may be due to factors such as excessive cutting speed, low feed speed, insufficient rigidity of the tool system, insufficient workpiece clamping force, workpiece shape or workpiece clamping method. At this time, measures should be taken Adjust the cutting amount, increase the stiffness of the tool system, increase the feed speed and other measures.

End cutting of milling cutter

In CNC milling of workpiece cavities such as molds, when the cut point is a concave part or a deep cavity, the extension of the milling cutter needs to be lengthened. If a long-edged milling cutter is used, due to the large deflection of the cutter, it is easy to vibrate and cause the cutter to break. Therefore, during the machining process, if only the cutting edge close to the end of the tool is involved in cutting, it is best to use a short-edge, long-shank milling cutter with a longer total tool length. When using a large-diameter milling cutter to process a workpiece on a horizontal CNC machine tool, due to the large deformation caused by the tool’s own weight, special attention should be paid to the problem of excellent end edge cutting. When it is necessary to use a long-edged milling cutter, the cutting speed and feed speed need to be significantly reduced.

End Mill Technology


Selection of cutting parameters
The selection of cutting speed mainly depends on the material of the workpiece to be processed; the selection of feed speed mainly depends on the material of the workpiece to be processed and the diameter of the milling cutter. Tool samples from some foreign tool manufacturers come with tool cutting parameter selection tables for reference. However, the selection of cutting parameters is also affected by many factors such as machine tools, tool systems, shape of the workpiece to be processed, and clamping methods. The cutting speed and feed speed should be adjusted according to the actual situation.
When tool life is the priority, the cutting speed and feed rate can be appropriately reduced; when the chip separation condition is not good, the cutting speed can be appropriately increased.
Selection of cutting methods
The use of down milling is beneficial to prevent blade protection and improve tool life. But there are two points that need to be paid attention to:
① If ordinary machine tools are used for processing, efforts should be made to eliminate the gap in the feeding mechanism;
② When there is an oxide film or other hardened layer formed by the casting or forging process remaining on the surface of the workpiece, up milling should be used.

Material requirements

Basic requirements for milling cutters to cut some materials

1) High hardness and wear resistance: At normal temperature, the cutting material must have sufficient hardness to cut into the workpiece; with high wear resistance, the tool will not wear and extend its service life.
2) Good heat resistance: The tool will generate a lot of heat during the cutting process, especially when the cutting speed is high, the temperature will be very high. Therefore, the tool material should have good heat resistance, not only at high temperatures but also It can maintain a high hardness and has the ability to continue cutting. This property of high-temperature hardness is also called thermohardness or red hardness.
3) High strength and good toughness: During the cutting process, the cutting tool must withstand a large impact force, so the cutting tool material must have high strength, otherwise it will be easily broken and damaged. Since milling cutters are subject to impact and vibration, the milling cutter material should also have good toughness so that it is not prone to chipping or chipping.
Commonly used materials for milling cutters
1) High-speed tool steel (referred to as high-speed steel, front steel, etc.), divided into two types: general-purpose and special-purpose high-speed steel.
It has the following characteristics:
a. The content of alloy elements tungsten, chromium, molybdenum and vanadium is relatively high, and the quenching hardness can reach HRC62-70. It can still maintain high hardness at a high temperature of 600℃.
b. The cutting edge has good strength and toughness and strong vibration resistance. It can be used to make tools with average cutting speed. For machine tools with poor rigidity, high-speed steel milling cutters can still cut smoothly.
c. It has good process performance, is relatively easy to forge, process and sharpen, and can also manufacture tools with more complex shapes.
d. Compared with cemented carbide materials, it still has disadvantages such as lower hardness, poor red hardness and poor wear resistance.
2) Cemented carbide: It is made of metal carbide, tungsten carbide, titanium carbide and metal binder mainly cobalt through powder metallurgy process.
Its main features are as follows:
a. It can withstand high temperatures and can still maintain good cutting performance at around 800-1000°C. When cutting, a cutting speed 4-8 times higher than that of high-speed steel can be used.
b. High hardness at room temperature and good wear resistance.
c. Low bending strength, poor impact toughness, and the blade is not easy to sharpen.
Commonly used cemented carbide can generally be divided into three categories:
① Tungsten-cobalt carbide (YG)
Commonly used grades are YG3, YG6, and YG8. The numbers indicate the percentage of cobalt content. The more cobalt content, the better the toughness and resistance to impact and vibration, but the hardness and wear resistance will be reduced. Therefore, the alloy is suitable for cutting cast iron and non-ferrous metals, and can also be used to cut high-impact blanks and quenched steel and stainless steel parts.
②Titanium-cobalt carbide (YT)
Commonly used grades include YT5, YT15, and YT30. The numbers indicate the percentage of titanium carbide. After cemented carbide contains titanium carbide, it can increase the bonding temperature of steel, reduce the friction coefficient, and slightly increase the hardness and wear resistance. However, it reduces the bending strength and toughness and makes the properties brittle. Therefore, the Alloy-like is suitable for cutting steel parts.
③ General purpose cemented carbide
Add appropriate amounts of rare metal carbides, such as tantalum carbide and niobium carbide, to the above two types of cemented carbide to refine the grains and improve their normal and high temperature hardness, wear resistance, bonding temperature and oxidation resistance. , can increase the toughness of the alloy. Therefore, this type of cemented carbide tool has better comprehensive cutting performance and versatility. Its brands include: YW1, YW2 and YA6, etc. Because of its relatively expensive price, it is mainly used for difficult Processing materials such as high-strength steel, heat-resistant steel, stainless steel, etc.

Relevant information

MACHINE CONDITIONTool holder in good condition and secure part holding fixture
TOOL CONDITIONUse cutting tool recommended for material being machined. Avoid excessive tool overhang.
FEEDS & SPEEDSStart with feeds and speeds recommended for material being machined
COOLANTCoolant flow must be adequate to avoid intermittent quenching and to flush chips promptly, avoiding the recutting of hardened chips.
1.ROUGH FINISHDull cutting edgeResharpen to original tool geometry
Wrong feeds & speedsIncrease speed – also try reduced feed
Wrong feeds & speedsIncrease feed (should always be over .001″ per tooth) – especially when
machining ductile or free machining materials. Also try reduced speed
Rough cutting edgeLightly hone cutting edge with fine grit diamond hone
Insufficient coolantIncrease coolant flow – review type of coolant
3.CHIPPED CUTTING EDGEPoor chip removalUse tool with larger flute space – larger diameter or fewer flutes
Recutting work hardened chipsIncrease coolant flow
VibrationIncrease rigidity of set-up, especially worn tool holders
Incorrect carbide gradeChange to tougher carbide grade
4.CHATTER MARKSInsufficient machine horsepowerUse tool with fewer flutes as correct feeds & speeds must be maintained
VibrationConsider climb milling
Use larger diameter cutter
Resharpen tool with more clearance
5.GLAZED FINISHFeed too lightIncrease feed
Dull cutting edgeResharpen tool to original geometry
Insufficient clearanceResharpen tool with more clearance
6.POOR TOOL LIFEExcessive crateringIncrease speed or decrease feed
Change to harder grade of carbide
Milling abrasive materialDecrease speed and increase feed
Increase coolant flow
Climb milling better than conventional milling
Milling surface scaleConventional milling better than climb milling
Milling hard materialsReduce speed – rigidity very important
Insufficient chip roomUse larger diameter tool
Delayed resharpeningPrompt resharpening to original geometry will increase tool life
Thermal cracked carbideMaintain adequate coolant flow at all times
Climb milling is cooler than conventional milling

Equipment maintenance

When the milling cutter axis line coincides with the workpiece edge line or is close to the workpiece edge line, the situation will be serious.

  1. Check the power and stiffness of the machine tool to ensure that the required milling cutter diameter can be used on the machine tool.
  2. The overhang of the tool on the spindle is as short as possible to reduce the impact of the milling cutter axis and the position of the workpiece on the impact load.
  3. Use the correct milling cutter pitch suitable for the process to ensure that there are not too many blades engaging the workpiece at the same time and causing vibration. On the other hand, ensure that there are enough blades when milling narrow workpieces or milling cavities. mesh with the workpiece.
  4. Make sure you use the feed per insert to get the right cut when the chips are thick enough to reduce tool wear. Indexable inserts with positive rake geometry for smooth cutting results and minimal power.
  5. Select a milling cutter diameter suitable for the width of the workpiece.
    6. Choose the correct leading angle.
  6. Place the milling cutter correctly.
  7. Use cutting fluid only when necessary.
  8. Follow the rules for tool maintenance and repair, and monitor tool wear.


Mold milling cutters are used to process mold cavities or punch forming surfaces. Mold milling cutters are evolved from end mills. According to the shape of the working part, they can be divided into three types: conical flat head, cylindrical ball head, and conical ball head. Carbide mold milling cutters are very versatile. In addition to milling various mold cavities, they can also replace hand files and grinding wheels to clean the burrs of casting, forging, and welding workpieces, as well as finish processing of certain forming surfaces. wait. The milling cutter can be used on pneumatic or electric tools, and its productivity and durability are dozens of times higher than grinding wheels and files.
The main purpose

Generally divided into

  1. Flat end milling cutter for rough milling, removing a large amount of blank, small area horizontal plane or contour fine milling.
  2. Ball-end milling cutters are used for semi-finishing and finishing milling of curved surfaces; small-sized ball-end milling cutters can be used for precision milling of steep surfaces/straight walls, small chamfers, and irregular contour surfaces.
  3. The flat-end milling cutter has a chamfer, which can be used for rough milling to remove a large amount of blank, and can also be used for fine milling of small chamfers on flat surfaces (as opposed to steep surfaces).
  4. Forming milling cutters include chamfering cutters, T-shaped milling cutters or drum cutters, toothed cutters, and internal R cutters.
  5. Chamfering cutter, the shape of the chamfering cutter is the same as the chamfering shape, and it is divided into milling cutters for round chamfering and oblique chamfering.
    6. T-shaped cutter can mill T-shaped slots.
  6. Tooth profile cutters can mill out various tooth profiles, such as gears.
  7. Rough leather cutter, a rough milling cutter designed for cutting aluminum and copper alloys, can be processed quickly.
    common problem
    Solution to insufficiently accurate dimensions:
  8. Overcutting:
    Reduce depth and width during cutting
  9. Machine or fixture lacks accuracy:
    Repair machines and fixtures
  10. Machine or fixture lacks rigidity:
    Change machine\fixture or cutting settings
  11. Too few blades:
    Use multi-edge end mills
    Milling cutters are developing rapidly. People in the industry call them rotary cutters. As shown in the figure “Milling Cutter 2”, they are only solid carbide milling cutters. In fact, more milling cutters are used in hole processing and cavity processing. This kind of milling cutter Most of them are installed with blades!

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