1. What Exactly Is The Milling Insert?

Milling is a method of cutting and processing workpieces on a milling machine using a milling cutter. It is widely applied in fields such as mechanical manufacturing. The following is an introduction to it:

The Principle of Milling

During milling, the milling cutter is mounted on the spindle of the milling machine and performs a rotating primary motion. The workpiece, on the other hand, is installed on the worktable. Through the movement or rotation of the worktable, the feed motion is achieved. The cutting edges of the milling cutter interact with the surface of the workpiece, gradually removing the excess material from the workpiece to machine it into the desired shape and size.

2. Milling Insert Types: 

 

Following are various types of milling inserts available that perform different tasks:

1）Face Milling Inserts

Face milling Inserts: Face milling is mostly done with the end teeth of a straight shank, taper shank milling cutter or disc milling cutter with a smaller main deflection angle. Through the movement of the milling cutter, a plane perpendicular to the milling cutter axis is machined. The milling cutter mainly used for milling planes is called a face milling cutter. 

Used for large surface processing with high efficiency.

Common types are as follows:

• SNMX, SPKN, SDKN, SEKT
• SPMT, SEMT
• SNGX, SEET, SZMX, SEEN, SEMR, HNMX, XNGX

2) Square Shoulder Milling Inserts

High machining accuracy: The insert design enables 90° right-angle shoulder machining with high contour accuracy, suitable for scenarios with strict requirements on shoulder dimensions and surface quality (e.g., molds, box-type parts). 

Strong versatility: Can balance plane milling and right-angle shoulder machining, reducing tool change times and improving machining efficiency, especially for multi-process machining of complex workpieces.

Common types are as follows:

• APMT
• APKT
• ADMT
• TPKT
• ANMX
• ANKT
• LNGU
• WNMU
• XNEX-GL/GM 

3) Profile Milling Inserts

Mainly used for three-dimensional processing of free shapes such as complex contours, curved surfaces, mold cavities, etc. They are usually installed on profile milling cutters or ball-end milling cutter bodies to meet the needs of high-speed, high-precision multi-axis linkage cutting. Common types are as follows:
Common types are as follows:

• RPMW
• RPMT
• ROMT
• RPMT
• RDKT 

4) High-Feed Milling Inserts

The unique edge design (e.g., large helix angle, sharp cutting edge) can significantly increase the feed rate and shorten processing time, suitable for high-efficiency rough machining. Adopts a cutting mode of small depth of cut and high feed, with low radial cutting force, reducing machine tool load and vibration, suitable for machining thin-walled parts, slender shafts and other deformable parts.

Common types are as follows:

• LNGU
• LOGU
• BLMP
• SEMT-GM
• SEER-GM
• SOMT
• SDMT
• SDMW
• LPGT
• EPNW 

5) Positive Mount Milling Inserts

• CNHX, LNKT, LNKX

 

3. Wodenco Milling Inserts Application scenarios

Carbide milling inserts applications:

🔧 1. General Metalworking

• Used for machining steel, stainless steel, cast iron, alloy steel, etc. 
• Suitable for face milling, end milling, profile milling, and slot milling 

🏭 2. Automotive Industry

• Applied to parts like engine blocks, brake discs, gear housings, and transmission components 
• Ideal for high-efficiency batch processing and precision machining 

✈️ 3. Aerospace Industry

• Used for milling aluminum alloys, titanium alloys, and nickel-based high-temperature alloys 
• Requires inserts with high toughness and thermal stability 

🏗️ 4. Mold & Die Manufacturing

• For rough and finish milling of mold cavities, mold cores, and complex 3D surfaces 
• Demands high dimensional accuracy and excellent surface finish 

🔩 5. General Machinery Components

• Machining of parts such as gears, shafts, housings, and mechanical parts 
• Typically used in medium-load and cost-effective machining applications 

📏 6. Precision Parts Manufacturing

• Light-load, high-precision milling on small CNC machining centers 
• Commonly uses triangular or trapezoidal-shaped inserts for finishing
  

4. Description of main grades of milling inserts

WO7130 Suitable for milling of ISO P, M materials, especially for machining of materials with hardness below 30 HRC.

The special proportion of the matrix effectively improves the wear resistance and toughness and reduces the risk of breakage. Combined with the latest nano coatings,the overall performance is excellent in high feed milling.

WO7120 Suitable for milling of ISO P, M, K materials,especially for machining of materials with hardness of 35-50 HRC. 

With excellent wear resistance and toughness and the latest multi-component nano coating,showsexcelient high temperature hardness.

WO9220 Suitable for milling of ISO P,M,K materials, especially for machining of materials with hardness of 40-45 HRC. Apply for AITiN and TiSiN double-layer coating structure has good strength, toughness and wear resistance, reduces the extension of longitudinal cracks, and effectively improves the chipping resistance of the coating.

WO9240 Suitable for milling of stainless steel, titanium alloy and high-temp alloy.

The new composition and matrix structure design,high temperature resistance and toughness are taken into account,and its wear resistance is further improved.

WO7325 Suitable for milling of steel.

WO3220 Suitable for milling of cast iron.

5. Common rules of select and use milling cutter

    Generally, select process of milling cutter consider the below several respects to select: 

1) Part shape (consider the manufacture moulding surface): generally, the manufacture moulding surface able to be divided into plane, deep section, cavity groove, screw and others, different manufacture moulding surface used cutters are different, example the round angle milling cutter able to milling convex curve, but unable to milling concave curve.

2) Material:consider the cutting manufacturing performance, cutting modeling, hardness, contain alloy elements and other respects. Generally, the cutter manufacturer divided the materials into steel, stainless steel, cast iron, nonferrous metal, high temperature alloy, titanium alloy and hardened materials.

3) Machining condition: the machining condition includes system stability of machine fixture workpiece and cutter handle install and clip situation and others.

4) System stability of machine-fixture-workpiece: this need to know well about the applicable power of machine, main shaft type and specification, the machine used age limit and others, and need to combine with the long suspension stretch quantity of cutter handle and the axial/radial circle jump situation.

5) Machining type and subtype: this includes square shoulder milling, plane milling, profile modeling milling and others need to be combined with characteristics of cutter to select the cutter.

2. Selection of milling cutter geometry angle

(1) Selection of front angle. The front angle of the milling cutter should be confirmed according to the materials of the cutter and workpiece. Frequently has shocks during milling, so should guarantee the cutting blade has higher strength. The front angle of milling cutter smaller than cutting front angle of lathe cutter under general situation; high speed steel need bigger than harden alloy cutter; additionally, because more bigger deformation of cutting during milling the plasticity materials, so should select bigger front angle; the front angle should smaller when milling fragile materials; still able to adopt negative front angle when machining big strength and high hardness materials. The detail value of the front angle shown as table 5-1.

 

    Table 5-1  Reference value of front angle of milling cutter  [Unit:(°)]

Workpiece material	Rm/MPa	High speed steel milling cutter	Carbide  alloy cutter
Steel	<600	20	15
	600~1000	15	-5
	>1000	12~10	-15~-10
Cast iron		5~15	-5~5

(2）Selection of cutting edge inclination. The external circle helix angle β of the vertical milling cutter and column milling cutter are cutting edge inclination λ. This makes the cutter gear able to gradually cut in and cut out workpiece, improving the stability of milling. Increase β then can make the actual front angle increasing, cutting blade more sharp, at the same time, also make cuttings easily discharged. For the milling cutter which more narrower milling width, no more meanings increase helical angle β, so generally select β=0 or smaller value. The detail value of helical angle β is shown as table 5-2.

Table 5-2  Reference value of external circle helical angle of milling cutter  [Unit:(°)]

 

Milling cutter type	Helical gear column milling cutter		Vertical milling cutter	Three surface blade, two surface blade milling cutter
	Scatter teeth	Dense teeth
Helical angle	45~60	25~30	30~45	15~20

 

（3）Selection of main drift angle and sub drift angle. Performance of surface milling cutter’s main drift angle and the influence to the milling process, same to the performance and influence of lath cutter drift angle in lathing. The common main drift angles are 45°, 60°, 75° and 90°, better rigidity of the technology system, select small value; select big value reversely, the main drift angle selection shown as table 5-3. Generally, the sub drift angle is 5° ~10°. The column milling cutter only has a cutting blade, no sub cutting blade, so no sub drift angle, the main drift angle is 90°.

 

Table 5-3  Selection of main drift angle

90° main drift angle	45° main drift angle	Round cutter blade cutter
1. Thin wall parts 2. Badder install and  clip parts 3. The fields where required accurate 90° angle                  modeling	1. First choice of common working steps 2. Reduce the vibration of big suspension machining 3. Reduce cutting chips thickness,                                                      improve production ratio	The most tough cutting blade which able to multiply times shift position  Most thin cuttings, most suitable to anti heat alloy machining Common cutters

3. Selection of blade groove shape  Selection of milling cutter blade groove (check table 5-4), surface performance of machined surface, surface quality and others have important meanings.

 

Table 5-4  Selection of blade groove shape

Light type cutting groove shape-L	Common groove shape-M	Heavy type groove shape-H
1. Sharp positive front angle cutting blade2. Stable cutting performance 3. Low feeding quantity 4. Low machine power 5. Low cutting force requirements	1. Common groove shape-M 2. Positive front angle groove shape which  used in mix machining 3. Middle feeding quantity	Used in highest        safety performance            requirements and  big feeding quantity

 

4. Selection of teeth quantity  Selection of milling cutter teeth quantity (check table 5-5) mainly consider the dredge and density degree of teeth distance, the dredge and density degree of teeth distance have important influence on machining surface quality, discharge chips and cutter teeth anti shock degree and others.

 

Table 5-5  Selection of teeth quantity

Dredge teeth distance	Density teeth distance	Ultra density teeth distance
To achieve highest production efficiency when stability and  power are limit, able to use unequal teeth distance or reduce blade quantity.   Able to be applied  in long suspension depth cutter, smaller size machines, example the cutter handle with awl is 40°	Common milling and mix machining	The max blade quantity,              short cuttings materials         and anti heat materials            which to obtain the best production ratio                under  stable working situation

 

6. During milling, because of the influence of workpiece materials, cutting parameters, cutter geometry parameters and others, it will frequently occur the appearance that cutter wear, blade broken, build up edge and others. Shown as table 4-6, those are solutions of several common problems.

Problems		Reasons	Solutions
Rear cutter surface  wear	Too quick wear will caused bad surface quality or over tolerance	1. Too high cutting speed 2. No enough anti wear performance 3. Too low each tooth feeding quantity Fz	1. Reduce cutting speed Vc 2. Select the grade more anti wear 3. Improve each tooth feeding quantity Fz
	Too big wear causedshort cutter working life	1. Vibration 2. Cuttings cutting again 3. Form burr on parts 4. Bad surface quality 5. Generate heat 6. Too big noise	1. Improve each tooth feeding quantity Fz 2. Downward milling 3. Use compress air for valid discharge chips Check the recommended cutting parameters
Moon valley wear	Too big wear weaken the cutting blade.Damage of cutting blade rear boundary will caused surface quality reducing	Because too high cutting temperature on front cutter surface and caused expansion wear	1. Select Al₂O₃coating layer grade2. Select and use positive front angle blade groove shape Firstly reduce the cutting speed to reduce the temperature, then reduce the feeding quantity
Plasticity   deformation	Cutting blade plasticity deformation, down collapse or rear cutter surface concave, caused that bad cuttings control, bad surface quality and blade broken	Too high cutting temperature and pressure	1. Select the grade more anti wear (more hard) 2. Reduce cutting speed Vc 3. Reduce each tooth feeding quantity Fz
Blade broken	Partial cutting blade which not join cutting damage because cuttings shock. The up cutter surface and support of blade maybe damaged, caused bad surface veins and too big rear cutter surface wear	Cuttings back to cutting blade	1. Select the grade more better roughness 2. Select the blade with more solid cutting blade 3. Improve cutting speed Vc 4. Select positive front angle groove shape 5. Reduce feeding quantity when cutting start 6. Improve stability
	Thin shattered cutting blade caused surface quality come to be bad and rear cutter surface over wear	1. Too fragile blade 2. Too weak cutter groove shape 3. Build up edge	1. Select the grade more better roughness 2. Select the blade which more higher strength groove shape strength 3. Improve cutting speed V or select positive front angle groove shape 4. Reduce feeding quantity when cutting start
Ditch groove wear	Ditch groove wear will caused surface quality come to be bad and cutting blade broken	1. Manufacture harden materials 2. Surface skin and rust skin	1. Reduce cutting speed Vc 2. Select the grade more better roughness 3. Improve cutting speed Vc

 

Problems		Reasons	Solutions
Thermal flaws	Small Cracks perpendicular  to the cutting edge can cause the blade to break and the surface quality to deteriorate.	The thermal flaws which caused by temperature  change is caused by interval machining and period supply cutting liquid	1. Select the roughness grade which able to anti thermal shock 2. Enough supply cutting liquid, or adopt dry cutting
Build-up edge (BU.E)	The build-up edge will caused the surface quality reduced, will caused cutting blade broken when remove the build up edge.	1. Too low cutting areatemperature 2. The materials easily spliced, such as low carbon steel, stainless steel and aluminum	1. Reduce cutting speed Vc 2. Renewal more suitable blade groove shape
	Workpiece material spliced  on cutting blade	1. Low cutting speed Vc 2. Low each tooth feeding quantity Fz 3. Negative front angle groove shape 4. Bad surface quality	1. Reduce cutting speed Vc 2. Improve each tooth feeding quantity Fz 3. Select positive front angle groove shape 4. Use oil fog or cutting liquid
Vibration		Bad fixture rigidity	1. Analyse direction of cutting force and provide enough brace or improve fixture 2. Through reduce back cutter feeding quantity ap 3. Select the positive front angle cutting, dredge teeth and uneven teeth distance cutter 4. Select the L groove shape with small round angle radius and small parallel blade band
		Bad Workpiece axial rigidity	1. Consider the square shoulder cutter with positive front angle groove shape (90° main drift angle) 2. Select the blade with groove shape L 3. Reduce axial cutting force 4. More lower back cutter feeding quantity, smaller round angle radius and parallel blade band 5. Select the dredge cutter with uneven teeth distance
		Too long cutter suspension stretching	1. Make suspension stretch smallest 2. Use the dredge cutter with uneven teeth distance 3. Balance radial and axial cutting force 4. Improve each tooth feeding quantity Fz 5. Use light type cutting blade groove shape L/M 6. Reduce axial back cutter feeding quantity ap 7. Use upward milling in fine machining
		Use the main shaft milling square shoulder with bad rigidity	1. Do best to select smaller cutter diameter 2. Select positive front angle, light and quick cutting cutter and blade 3. Try to upward milling
		Vibration at round angle position	Use big round angle radius and reduce feeding quantity during programming

 

Problems		Reasons	Solutions
Cuttings  blocked	Generally it existing obstacles when process full groove milling, easily occur this situation especially at machining the long chips materials	1. Blade broken and cracked 2. Cuttings cutting again	1. Use cutting liquid or compress air to improve discharge chips 2. Reduce each tooth feeding quantity Fz 3. Divide deep cutting into several times feeding 4. Try to upward milling in deep groove machining 5. Use dredge teeth cutter
Cuttings cuttingagain	Occur when full groove milling and machining section cavity, especially in titanium alloy materials. Also frequently occur this situation when milling deep section cavity and concave holes in vertical machine	1. Cutting blade broken 2. Damage working life and safety of cutter 3. Cuttings blocked	1. Use cutting liquid or enough cutting liquid to discharge chips 2. Change cutter position and cutter path 3. Reduce each tooth feeding quantity Fz Divide deep cutting into several times feeding