Milling Cutter


May 23, 2017 Facebook Twitter LinkedIn Google+ milling machines



A cutter that is a rotary tool with one or more teeth for milling. When the work of the knife teeth in turn intermittently cut the workpiece allowance. Milling cutters are mainly used for machining flat surfaces, steps, grooves, forming surfaces and cutting workpieces on milling machines.

Table of content

1.Product type

1.1Cylindrical cutter

1.2Face milling cutter

1.3End mills

1.4Three blade cutter

1.5Angle cutter

1.6Saw blade cutter

1.7T-shaped cutter

2. Product structure

2.1Integral

2.2Integral Weld

2.3Inlay

2.4Transpositionable

3. About milling

3.1 Related knowledge

3.2 Milling method

4. Product classification

4.1 sharp tooth cutter

4.2 shovel cutter

5. Main use

6. Frequently Asked Questions

7. Use method

7.1 Milling of the milling cutter

7.2 Milling of the cutter

7.3 End edge cutting of the milling cutter

7.4 Selection of cutting parameters

7.5 Selection of cutting methods

8. Material requirements

8.1 Milling cutter part of the basic requirements of the material

8.2Common Milling Materials

9. Equipment maintenance

10. Mold

11.Other references

12.List of Milling Cutter manufacturers

1.Product type

1.1Cylindrical cutter

For flat milling machine on the plane. Knife teeth distributed in the circumference of the cutter, according to the tooth is divided into straight and helical teeth two. According to the number of teeth and coarse teeth two teeth. Spiral teeth coarse teeth milling teeth less teeth, high tooth strength, chip space, suitable for rough processing; fine tooth cutter for finishing.

1.2Face milling cutter

Also known as the milling cutter, for vertical milling machine, milling machine or milling machine milling machine on the plane, the end and circumference are knife teeth, but also coarse and fine teeth of the points. Its structure has the whole type, the tooth type and the indexable type 3 kinds.

1.3End mills

For machining trenches and stepped surfaces, etc., the teeth in the circumference and end face, the work can not be fed along the axial. When the end mill through the center of the end teeth, the axial feed.

1.4Three blade cutter

For the processing of various trenches and stepped surfaces, both sides and circumference are knife teeth.

1.5Angle cutter

For milling into a certain angle of the groove, there are two kinds of single angle and double angle cutter.

1.6Saw blade cutter

Used to process the deep groove and cut the workpiece, the circle has more teeth. In order to reduce the friction at the time of milling, the teeth on both sides of the 15 ‘~ 1 ° sub-deflection. In addition, there are keyway cutter, dovetail slot cutter, T-slot cutter and a variety of milling cutter and so on.

1.7T-shaped cutter

Used to milling T-shaped groove.

2. Product structure

2.1Integral

Knife body and knife teeth made of one.

2.2Integral Weldy

The knife teeth are made of hard alloy or other abrasive tool material and brazed to the cutter body.

2.3Inlay

The knife teeth are fastened to the body by means of mechanical clamping. This changeable tool teeth can be the head of the overall tool material, or it can be the tip of the tool material. The cutter head mounted on the blade body is known as the internal blade grinding type; the cutter head is sharpened on the fixture.

2.4Transpositionable

(See indexable tool): This structure has been widely used in face milling cutter, end mill and three blade cutter.

3. About milling

3.1 Related knowledge

To understand the milling cutter, we must first understand the milling knowledge

In the optimization of milling results, the cutter blade is another important factor in any milling at the same time if the number of cutting blades at the same time more than one is the advantage, but at the same time to participate in cutting the number of blades is too short, A cutting edge can not be cut at the same time, the required power and the cutting edge of the cutting involved in the number of cutting on the chip formation process, the cutting edge load and processing results, the cutter relative to the workpiece position played an important role. In the face milling, with a cutting width of about 30% greater than the cutter and the cutter position close to the center of the workpiece, then the chip thickness change is not. The cut-out chip thickness is slightly thinner than the cutting thickness at the center of cutting.

In order to ensure the use of a sufficiently high average chip thickness / per tooth feed, the number of milling cutter teeth suitable for this process must be correctly determined. The pitch of the milling cutter is the distance between the effective cutting edges. According to this value will be divided into three types of milling cutter – dense tooth cutter, sparse tooth cutter, special teeth cutter.

And the chip thickness of the milling is related to the main angle of the face milling cutter, the main angle is the main cutting edge of the blade and the workpiece surface angle between the main 45 degrees, 90 degrees angle and round blade, cutting force The direction change will vary greatly with the major declination: the main declination of 90 degrees of the milling cutter mainly produce radial force, the role of the feed direction, which means that the surface will be processed will not bear too much pressure , For the masonry structure of the workpiece is relatively reliable.

The main angle of 45 degrees of the milling cutter its radial cutting force and the axial is roughly equal, so the resulting pressure is more balanced, the requirements of the machine power is relatively low, especially suitable for milling to produce broken chip chips Workpiece.

A round blade cutter means that the main declination changes continuously from 0 to 90 degrees, depending on the depth of the cut. This blade cutting edge strength is very high, because the long cutting edge in the direction of the chip is relatively thin, so suitable for large feed, along the radial direction of the blade cutting force in the direction of change, and the pressure generated in the process Will depend on the cutting depth. The development of modern blade geometric groove shape makes the circular blade have a smooth cutting effect, the machine power demand is low, good stability and so on. Today, it is no longer an effective coarse milling cutter, has a wide range of applications in face milling and vertical milling.

3.2 Milling method

There are two ways to feed the direction of the workpiece and the direction of rotation of the cutter:

The first is the smooth milling, the direction of rotation of the milling cutter and the cutting direction of the cutting are the same, at the beginning of cutting the cutter to bite the workpiece and cut the final chip.

The second is the reverse milling, the direction of rotation of the milling cutter and the direction of the cutting of the cutting are reversed. The milling cutter must slide on the workpiece before starting the cutting, starting with the cutting thickness of zero and cutting at the end of the cutting maximum.

In the three blade cutter, some milling or face milling, the cutting force in different directions. Milling, the cutter is just outside the workpiece, the direction of the cutting force should pay special attention. When the milling is done, the cutting force presses the workpiece against the table, and the cutting force causes the workpiece to leave the work table.

As the cutting effect of the best milling, usually preferred milling, only when the machine there is a thread gap problem or can not solve the problem of milling, only consider the reverse milling.

In the ideal situation, the diameter of the milling cutter should be larger than the width of the workpiece, the cutter axis should always be and the workpiece centerline slightly away from some distance. When the tool is placed on the cutting center, it is easy to produce burrs. Cutting the cutting edge into the cutting and exit cutting the direction of radial cutting force will continue to change, the machine tool spindle may vibrate and damage, the blade may be broken and the processing surface will be very rough, slightly lower from the center of the cutter, cutting force direction will no longer fluctuate – The milling cutter will get a preload. We can drive the center more than just in the center of the road.

When the cutter blade enters the cutting, the cutting edge is subjected to the impact load. The load depends on the cross section of the chip, the workpiece material and the cutting type. It is an important direction for the cutting edge and the workpiece to be properly engaged when cut and cut.

When the milling cutter axis is completely outside the width of the workpiece, the impact force at the time of cutting is carried by the outermost tip of the blade, which means that the initial impact load is borne by the most sensitive part of the tool. The cutter is also the last to leave the workpiece with the tip, which means that the blade is cut from the beginning to the cutting, the cutting force has been applied to the outermost tip until the impact of unloading so far. When the center line of the milling cutter is located on the edge of the workpiece, the blade is cut off when the chip thickness reaches the maximum, and the impact load reaches the maximum at the cutout. When the milling cutter axis is within the width of the workpiece, the initial impact load at the time of cutting is taken along the cutting edge by the distance from the most sensitive tip, and the blade is smoothed when the blade is retreated.

For each blade, it is important to cut the cutting edge away from the workpiece when the exit is to be made. The remaining material near the retractor may reduce the blade gap. When the chip from the workpiece along the blade rake face will produce an instantaneous tensile force and often produce burrs on the workpiece. This tensile force compromises the cutting edge safety in hazardous situations.

4. Product classification

4.1 sharp tooth cutter

In the flank face grinding a narrow blade to form the rear angle, because the cutting angle is reasonable, its life is higher. The tip of the tooth has a straight line, a curve and a broken line. Straight tooth back is often used for fine teeth finishing cutter. Curve and fold the teeth of the tooth strength is better, can withstand heavier cutting load, commonly used in coarse tooth cutter.

4.2 shovel cutter

Which is followed by the shovel (or shovel grinding) processing into the Archimedes spiral teeth back, the cutter with only after the re-grinding the front, to maintain the original tooth-shaped, for the manufacture of gear milling cutter Various forming cutter.

5. Main use

Generally divided into:
1, Flat head cutter, rough milling, removal of a large number of blanks, a small area of horizontal plane or contour fine milling.
2, Ball milling cutter, the surface of semi-fine milling and finishing; small ball cutter can be fine grinding steep surface / straight wall of the small chamfer there are irregular contours.
3, Flat head cutter with chamfering, rough milling can be done to remove a large number of rough, but also fine grinding fine flat surface (relative to the steep surface) small chamfer.
4, Forming cutter, including chamfering knife, T-shaped cutter or drum knife, tooth knife, within the R knife.
5, Chamfering knife, chamfering knife shape and chamfer the same shape, divided into milling chamfer and chamfer chamfering cutter.

6, T-type knife, can be milling T-slot.

7, Tooth cutter, milling all kinds of teeth, such as gear.

8, Thick leather knife, for aluminum and copper alloy cutting design of the rough cutter, can be quickly processed.

6. Frequently Asked Questions

Size is not accurate enough: Solution:

A. Excessive cutting
Reduce the depth and width of the cutting

B. The machine or fixture lacks accuracy
Repair machines and fixtures

C. The machine or fixture lacks rigidity
Change the machine \ fixture or cutting settings

D. The number of edges is too small
Use multi-blade end mills

7. Use method

7.1 Milling of the milling cutter

Machining center with milling cutter mostly accept the spring clip clamping method, when used in cantilever form. In the milling process, there may be times when the cutter is gradually extended from the tool holder so that it is complete and lost, so that the workpiece is scrapped. The reason is usually due to the fact that the hole between the tool holder and the cutter Oil film, the formation of clamping force due to inadequate. Milling cutter factory are generally coated with anti-rust oil, if the use of non-water cutting cutting oil, knife hole will be attached to a layer of mist oil film, sell knife handle and knife clip are stored in the oil film, Difficult to firmly clamp the handle, is processing in the milling cutter caused by loose and lost. So before the cutter is clamped, the cutter head and the knife should be the first hole with cleaning fluid cleaning clean, dry and then clamp.

When the diameter of the cutter is large, even if the knife handle and knife clip are very clean, or the possibility of loss of knife accident, then should be used to cut the gap with the handle and the corresponding side locking method.

Another problem that may occur when the milling cutter is clamped is that the milling cutter is breaking at the tool holder port. The reason is usually due to the long tooling time, the tool holder port has been worn as a cone, Replace the new tool holder.

7.2 Milling of the cutter

As the cutter and the knife between the folder is in a small gap, so the process is in the process of the knife may appear vibration scene. Vibration will make the cutter blade blade edge of the knife is not uniform, and the amount of expansion than the original value increases, affecting the machining accuracy and tool life. However, when the width of the groove is small, it is possible to make the tool vibrate and increase the amount of cutting to increase the required width. However, in this case, the maximum amplitude of the milling cutter should be 0.02 mm or less. For stable cutting. The smaller the vibration of the milling cutter in normal machining, the better.

When the tool vibration occurs, it should be considered to reduce the cutting speed and feed rate, such as both have been reduced by 40% is still in the larger vibration, you should consider reducing the amount of knife.

Such as the processing of fragmented resonance, the reason may be cutting speed is too large, the feed speed is just small, the tool system is not enough, the workpiece clamping force and the workpiece shape or workpiece clamping elements and other factors, this time should be accepted Adjust the amount of cutting, add the tool piece stiffness, progressive feed speed and other measures.

7.3 End edge cutting of the milling cutter

In the CNC milling of the mold cavity, etc., when the cutting point is a concave part or a deep cavity, the extension of the milling cutter is required. If the use of long-edge cutter, due to the larger deflection of the tool, easy to produce vibration and lead to damage to the tool. Therefore, in the process of processing, if only the end of the tool edge of the blade to participate in cutting, it is best to use the total length of the tool with a long length of long-edged cutter. In the horizontal CNC machine tools on the use of large diameter milling cutter workpiece, due to the deformation of the tool due to heavy deformation occurs, should pay more attention to the edge of the cutting edge of the title. It is necessary to use the long-edge cutter, you need to significantly reduce the cutting speed and feed speed.

7.4 Selection of cutting parameters

The choice of cutting speed depends on the material of the workpiece to be machined. The choice of feed speed depends mainly on the material of the workpiece and the diameter of the cutter. Cutting parameters of the selection at the same time by the machine tools, tool parts, the workpiece shape and the way of clamping and other factors, should be based on the practice of the situation to sell the cutting speed and feed speed.
When the tool life is given priority, the cutting speed and the feed rate can be appropriately reduced. When the cutting edge of the chip is not good, the cutting speed can be increased as appropriate.

7.5 Selection of cutting methods

Accept the milling tool to help protect the blade cover, can improve tool life. But there are two points to focus on:
① such as the acceptance of ordinary machine tool processing, should be the idea of eliminating the gap between the feed agencies;
② When the workpiece appearance of casting and forging process composed of oxide film or other hardening layer, it is appropriate to accept reverse milling.

8. Material requirements

8.1 Milling cutter part of the basic requirements of the material

1) high hardness and wear resistance: at room temperature, cutting part of the material must have enough hardness to cut into the workpiece; with high wear resistance, the tool is not wear, extend the service life.
2) good heat resistance: the cutting tool in the cutting process will produce a lot of heat, especially in the cutting speed is high, the temperature will be high, so the tool material should have good heat resistance, both at high temperatures still Can maintain a high hardness, can continue to cut the performance, this has the nature of high temperature hardness, also known as hot hard or red hardness.
3) high strength and good toughness: in the cutting process, the tool to bear a great impact, so the tool material to have a high strength, or easy to break and damage. As the milling cutter will be shock and vibration, therefore, milling cutter material should also have good toughness, it is not easy to chipping, fragmentation.

8.2Common Milling Materials

1) high-speed tool steel (referred to as high-speed steel, front steel, etc.), sub-general and special purpose high-speed steel two.
It has the following characteristics:
A, alloying elements tungsten, chromium, molybdenum, vanadium content is higher, quenching hardness up to HRC62-70. In the 600 ℃ high temperature, can still maintain a high hardness.
B, edge strength and toughness is good, strong anti-vibration, can be used to manufacture cutting speed of the general tool, for poor steel machine, the use of high-speed steel cutter, can still smooth cutting.
C, good process performance, forging, processing and grinding are relatively easy, you can also create a more complex shape of the tool.
D, compared with the cemented carbide materials, there are still low hardness, red hardness and poor wear resistance and other shortcomings.

2) Carbide: metal carbide, tungsten carbide, titanium carbide and cobalt-based metal binder made by the powder metallurgy process.
Its main features are as follows:
A, can withstand high temperatures, in the 800-1000 ℃ or so can still maintain a good cutting performance, cutting can be used when the high-speed steel than 4-8 times the cutting speed.
B, room temperature hardness, good wear resistance.
C, low bending strength, poor impact toughness, the blade is not easy to wear very sharp.
Commonly used carbide can generally be three categories:
① Tungsten Cobalt Carbide (YG)
Commonly used grades YG3, YG6, YG8, where the figures indicate the percentage of cobalt, the more cobalt, the better the toughness, the more shock and vibration, but will reduce the hardness and wear resistance. Therefore, the alloy is suitable for cutting cast iron and non-ferrous metals, can also be used to cut the impact of large rough and quenched steel and stainless steel pieces.
② Titanium-cobalt-based cemented carbide (YT)
Commonly used brands are YT5, YT15, YT30, figures represent the percentage of titanium carbide. Carbide containing titanium carbide, can improve the bonding temperature of steel, reduce the friction coefficient, and can improve the hardness and wear resistance, but reduces the bending strength and toughness, so that the nature of brittle, so the The alloy is suitable for cutting steel parts.
③ general carbide
In the above two kinds of hard alloy by adding the right amount of rare metal carbide, such as tantalum carbide and niobium carbide, etc., so that grain refinement, to improve its normal temperature hardness and high temperature hardness, wear resistance, bonding temperature and oxidation resistance So that the toughness of the alloy has increased, so this kind of carbide cutter has a good overall cutting performance and versatility, its grades are: YW1, YW2 and YA6, etc., because of its more expensive, mainly for difficult Processing materials, such as high-strength steel, heat-resistant steel, stainless steel and so on.

9. Equipment maintenance

Cutter
The situation will be severe when the milling cutter axis line and the workpiece edge line coincide with or close to the edge line of the workpiece.
a. Check the power and rigidity of the machine to ensure that the required milling cutter diameter can be used on the machine.
b. The amount of overhang of the tool on the spindle is as short as possible, reducing the effect of the milling cutter axis and the workpiece position on the impact load.
c. The correct milling cutter pitch suitable for this process is used to ensure that there are not too many blades at the same time that the blade is engaged with the workpiece to cause vibration. On the other hand, it is necessary to ensure that there is sufficient blade when milling a narrow workpiece or milling cavity And workpiece engagement.
d. Make sure that the feed per blade is used so that the correct cutting effect is achieved when the chip is thick enough to reduce tool wear. Using an anterior slotted indexable insert, resulting in a smooth cutting effect and the lowest power.
e. Select the diameter of the cutter that is suitable for the width of the workpiece.
f. Choose the correct main declination.
g. Place the cutter correctly.
h. Use cutting fluid only if necessary.
i. Follow the rules for tool maintenance and repair, and monitor tool wear.

10. Mold

The mold cutter is used to mold the mold cavity or punch forming surface. Mold milling cutter is developed by the end mill, according to the working part of the shape can be divided into conical flat head, cylindrical ball, cone-shaped ball three. Carbide die milling cutter is used in a wide range, in addition to milling a variety of mold cavity, but also instead of hand rasp and wheel grinding head to clean the casting, forging, welding parts of the flash, and some of the forming surface finishing Wait. The milling cutter can be used in pneumatic or electric tools to use, production efficiency and durability than the wheel and the file increased several times.

11.Other references

CNC Turning Machine
Universal Milling Machine
Horizontal Milling Machine
Vertical Milling Machine
Tapping Machine
Water Jet Cutting Machine
Plasma Cutting Machine
EDM – Electrical Discharge Machining
ERP – Enterprise Resource Planning
CAM – Computer Aided Manufacturing
CAD(Computer Aided Design)
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cnc router
cnc-lathe-machine-buyers
3d-printer
cnccomputer-numerical-control
cnc-grinding-machine
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cnc-machining

12.List of Milling Cutter manufacturers

ManufacturerHQProducts Built
Zhenjiang Scharp Machinery Tools Co., Ltd.Chinadrill bits, end mills, slitting saws, taps, milling cutters, carbide burrs, reamers.
CENTRIX-EG, Ltd.Chinaboring bars, boring bits, boring tools, carbide-tipped tools, drills, cutting tools, inserts, milling cutters, taps.
Karned ToolsCzech Republicboring and facing heads, drills, cutting tools, coated, millers, milling cutters, toolholder with coupleable drive.
LMT BelinFranceboring devices, carbide-tipped tools, diamond cutting tools, engraving tools, milling cutters, reamers.
GühringGermanydrilling, threading, milling cutters, gun drills, PKD/CBN, countersinking, reaming, tool holders, automatic tool dispensers, chucks.
Paul Dümmel Werkzeugfabrik GmbHGermanyultramini, rotaline, hardline, minicut, system DED, system ZSR, system ZTP, mikromill, circular milling, minimill cutting edges, slotting cutter, milling cutter, broaching.
AVANTECGermanycutting tools, coated, end millers, inserted blade milling cutters, inserts, milling cutters, side and face cutters.
Karl-Heinz ArnoldGermanyautomatic tool dispensers, drill chucks, cutting tools, coated, end millers, milling cutters, tool holders.
B.G. BertulettiItalydrills, circular saw blades, milling cutters,hard metal inserts, reamers, shear knives, threading tools.
BPKKorea, Republic ofindexable inserts of aluminium oxide, inserts, metal cutting tool, milling arbors, milling cutters, spade drills.
BT Bienne Special Tools SarlSwitzerlandhard-metal special tools, drill bits, milling cutters, reamers, gravers, gauges.
BKJ Digital Design and DevelopmentUScombined drill & countersinks and drills, milling cutters, spotting drills.
Whitney Tool Co., Inc.UScustom-made cutting tools, woodruff style slotting, keyseat milling cutters, counterbores, counterbore pilots, t-slot, dovetail, milling cutters.
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