The brazing technology and brazing material selection directly determine the quality level of carbide burr.
The welding technology of carbide rotary burrs is one of the key factors that affect their quality. The choice of welding materials and welding processes directly determines the quality level of the carbide rotary burrs.
Selection of welding materials: Carbide rotary burrs use a core-sandwich silver brazing material, which has silver at both ends and a copper alloy core layer in between. The welding temperature for this material is around 800°C, which is much lower compared to the 1100°C welding temperature required for copper brazing materials. This significantly limits the damage to the carbide properties, reduces welding stress, prevents microcracks in the carbide, and provides better welding strength.
Selection of welding methods: There are currently two main welding methods in the market: flat-bottom silver brazing and tail-hole copper brazing. Flat-bottom silver brazing has a simpler structure, lower welding stress, and lower required welding temperature, which better preserves the performance of the alloy and steel handle. On the other hand, tail-hole copper brazing can save some carbide material and is cheaper, but the higher welding temperature may cause damage to the carbide properties.
Welding equipment and process: Using automatic welding machines is a crucial part of the process. In the automatic welding process, the carbide tip and steel handle can automatically align for brazing without manual intervention, greatly ensuring the stability of the welding quality and excellent coaxiality between the steel handle and carbide tip after welding.
As a company with over ten years of experience in carbide material research and development, Chengdu Baboshi Cutting Tools has a deep understanding of carbide material performance. During the welding process of rotary burrs, we use fully automated flat-bottom silver brazing technology, which greatly protects the alloy's performance and ensures excellent coaxiality between the steel handle and the carbide tip.
Annular Cutter: A Professional Tool to Overcome the Challenges of Drilling Stainless Steel
In the field of industrial machining, stainless steel has become a key material in manufacturing due to its excellent corrosion resistance, high strength, and good toughness. However, these same properties also pose significant challenges for drilling operations, making stainless steel drilling a demanding task. Our annular cutter, with its unique design and outstanding performance, provides an ideal solution for efficient and precise drilling in stainless steel.
Ⅰ. Challenges and Core Difficulties in Drilling Stainless Steel
1.High Hardness and Strong Wear Resistance:
Stainless steel, particularly austenitic grades like 304 and 316, has high hardness that significantly increases cutting resistance—over twice that of regular carbon steel. Standard drill bits dull quickly, with wear rates increasing by up to 300%.
2.Poor Thermal Conductivity and Heat Accumulation:
The thermal conductivity of stainless steel is only one-third that of carbon steel. The cutting heat generated during drilling cannot dissipate quickly, causing localized temperatures to exceed 800°C. Under such high-temperature and high-pressure conditions, alloy elements in stainless steel tend to bond with the drill material, leading to adhesion and diffusion wear. This results in drill bit annealing failure and workpiece surface hardening.
3.Significant Work Hardening Tendency:
Under cutting stress, some austenite transforms into high-hardness martensite. The hardness of the hardened layer can increase by 1.4 to 2.2 times compared to the base material, with tensile strength reaching up to 1470–1960 MPa. As a result, the drill bit is constantly cutting into increasingly harder material.
4.Chip Adhesion and Poor Chip Evacuation:
Due to the high ductility and toughness of stainless steel, chips tend to form continuous ribbons that easily adhere to the cutting edge, forming built-up edges. This reduces cutting efficiency, scratches the hole wall, and leads to excessive surface roughness (Ra > 6.3 μm).
5.Thin Plate Deformation and Positioning Deviation:
When drilling sheets thinner than 3mm, the axial pressure from traditional drill bits can cause material warping. As the drill tip breaks through, unbalanced radial forces may lead to poor hole roundness (commonly deviating by more than 0.2mm).
These challenges make conventional drilling techniques inefficient for stainless steel processing, calling for more advanced drilling solutions to effectively address these issues.
Ⅱ. Definition of Annular Cutter
An annular cutter, also known as a hollow drill, is a specialized tool designed for drilling holes in hard metal plates such as stainless steel and thick steel sheets. By adopting the principle of annular (ring-shaped) cutting, it overcomes the limitations of traditional drilling methods.
The most distinctive feature of the annular cutter is its hollow, ring-shaped cutting head, which removes only the material along the hole's perimeter rather than the entire core, as with conventional twist drills. This design dramatically enhances its performance, making it far superior to standard drill bits when working with thick steel plates and stainless steel.
Ⅲ. Core Technical Design of the Annular Cutter
1.Three-Edge Coordinated Cutting Structure:
The composite cutting head consists of outer, middle, and inner cutting edges:
Outer Edge: Cuts a circular groove to ensure precise hole diameter (±0.1mm).
Middle Edge: Bears 60% of the main cutting load and features wear-resistant carbide for durability.
Inner Edge: Breaks the material core and aids in chip removal. The uneven tooth pitch design helps prevent vibration during drilling.
2.Annular Cutting & Chip-Breaking Groove Design:
Only 12%–30% of the material is removed in a ring shape (core retained), reducing cutting area by 70% and lowering energy consumption by 60%. Specially engineered spiral chip grooves automatically break chips into small fragments, effectively preventing ribbon-shaped chip entanglement—a common issue when drilling stainless steel.
3.Central Cooling Channel:
Emulsion coolant (oil-to-water ratio 1:5) is directly sprayed to the cutting edge through a central channel, reducing the temperature in the cutting zone by over 300°C.
4.Positioning Mechanism:
The center pilot pin is made of high-strength steel to ensure accurate positioning and prevent drill slippage during operation—especially important when drilling slippery materials like stainless steel.
Ⅳ. Advantages of Annular Cutters in Drilling Stainless Steel
Compared to traditional twist drills that perform full-area cutting, annular cutters remove only a ring-shaped section of the material—retaining the core—which brings revolutionary advantages:
1.Breakthrough Efficiency Improvement:
With a 70% reduction in cutting area, drilling a Φ30mm hole in 12mm-thick 304 stainless steel takes just 15 seconds—8 to 10 times faster than using a twist drill. For the same hole diameter, annular cutting reduces workload by over 50%. For example, drilling through a 20mm-thick steel plate takes 3 minutes with a traditional drill, but only 40 seconds with an annular cutter.
2.Significant Reduction in Cutting Temperature:
Central cooling fluid is directly injected into the high-temperature zone (optimal ratio: oil-water emulsion 1:5). Combined with layered cutting design, this keeps the cutter head temperature below 300°C, preventing annealing and thermal failure.
3.Guaranteed Precision and Quality:
Multi-edge synchronized cutting ensures automatic centering, resulting in smooth, burr-free hole walls. Hole diameter deviation is less than 0.1mm, and surface roughness is Ra ≤ 3.2μm—eliminating the need for secondary processing.
4.Extended Tool Life and Reduced Costs:
The carbide cutting head withstands the high abrasiveness of stainless steel. Over 1,000 holes can be drilled per regrind cycle, reducing tool costs by up to 60%.
5.Case Study:
A locomotive manufacturer used annular cutters to drill 18mm holes in 3mm-thick 1Cr18Ni9Ti stainless steel base plates. The hole pass rate improved from 95% to 99.8%, roundness deviation decreased from 0.22mm to 0.05mm, and labor costs were reduced by 70%.
Ⅴ. Five Core Challenges and Targeted Solutions for Drilling Stainless Steel
1.Thin-Wall Deformation
1.1Problem: Axial pressure from traditional drill bits causes plastic deformation of thin plates; at breakthrough, radial force imbalance leads to oval-shaped holes.
1.2.Solutions:
Backing Support Method: Place aluminum or engineering plastic backing plates under the workpiece to distribute compressive stress. Tested on 2mm stainless steel, ovality deviation ≤ 0.05mm, deformation rate reduced by 90%.
Step Feed Parameters: Initial feed ≤ 0.08 mm/rev, increase to 0.12 mm/rev at 5mm before breakthrough, and to 0.18 mm/rev at 2mm before breakthrough to avoid critical speed resonance.
2. Cutting Adhesion and Built-Up Edge Suppression
2.1.Root Cause: Welding of stainless steel chips to the cutting edge at high temperature (>550°C) causes Cr element precipitation and adhesion.
2.2.Solutions:
Chamfered Cutting Edge Technology: Add a 45° chamfer edge 0.3-0.4mm wide with 7° relief angle, reducing blade-chip contact area by 60%.
Chip-Breaking Coating Application: Use TiAlN coated drill bits (friction coefficient 0.3) to reduce built-up edge rate by 80% and double tool life.
Pulsed Internal Cooling: Lift drill every 3 seconds for 0.5 seconds to allow cutting fluid penetration at adhesion interface. Combined with 10% extreme pressure emulsion containing sulfur additives, temperature in cutting zone can drop by over 300°C, significantly reducing welding risk.
3. Chip Evacuation Issues and Drill Jamming
3.1.Failure Mechanism: Long strip chips entangle the tool body, blocking coolant flow and eventually clogging the chip flutes, causing drill breakage.
3.2.Efficient Chip Evacuation Solutions:
Optimized Chip Flute Design: Four spiral flutes with 35° helix angle, increased flute depth by 20%, ensuring each cutting edge chip width ≤ 2mm; reduces cutting resonance and cooperates with spring push rods for automatic chip clearing.
Air Pressure Assisted Chip Removal: Attach 0.5MPa air gun on magnetic drill to blow away chips after each hole, reducing jamming rate by 95%.
Intermittent Drill Retraction Procedure: Fully retract drill to clear chips after reaching 5mm depth, especially recommended for workpieces thicker than 25mm.
4. Curved Surface Positioning and Perpendicularity Assurance
4.1.Special Scenario Challenge: Drill slipping on curved surfaces like steel pipes, initial positioning error >1mm.
4.2.Engineering Solutions:
Cross Laser Positioning Device: Integrated laser projector on magnetic drill projects crosshair on curved surface with ±0.1mm accuracy.
Curved Surface Adaptive Fixture: V-groove clamp with hydraulic locking (clamping force ≥5kN) ensures drill axis parallel to surface normal.
Stepwise Starting Drill Method: Pre-punch 3mm pilot hole on curved surface → Ø10mm pilot expansion → target diameter annular cutter. This three-step method achieves verticality of Ø50mm holes at 0.05mm/m.
Ⅵ.Stainless Steel Drilling Parameter Configuration and Cooling Fluid Science
6.1 Golden Matrix of Cutting Parameters
Dynamic adjustment of parameters according to stainless steel thickness and hole diameter is the key to success:
Workpiece Thickness
Hole Diameter Range
Spindle Speed (r/min)
Feed Rate (mm/rev)
Coolant Pressure (bar)
1-3 mm
Ø12-30 mm
450-600
0.10-0.15
3-5
3-10 mm
Ø30-60 mm
300-400
0.12-0.18
5-8
10-25 mm
Ø60-100 mm
150-250
0.15-0.20
8-12
>25 mm
Ø100-150 mm
80-120
0.18-0.25
12-15
Data compiled from austenitic stainless steel machining experiments.
Note: Feed rate < 0.08 mm/rev aggravates work hardening; > 0.25 mm/rev causes insert chipping. Strict matching of speed and feed ratio is necessary.
6.2 Coolant Selection and Usage Guidelines
6.2.1.Preferred Formulations:
Thin Plates: Water-soluble emulsion (oil:water = 1:5) with 5% sulfurized extreme pressure additives.
Thick Plates: High-viscosity cutting oil (ISO VG68) with chlorine additives to enhance lubrication.
6.2.2.Application Specifications:
Internal Cooling Priority: Coolant delivered through drill rod center hole to the drill tip, flow rate ≥ 15 L/min.
External Cooling Assistance: Nozzles spray coolant onto chip flutes at a 30° inclination.
Temperature Monitoring: Replace coolant or adjust formulation when cutting zone temperature exceeds 120°C.
6.3 Six-Step Operation Process
Workpiece clamping → Hydraulic fixture locking
Center positioning → Laser cross calibration
Drill assembly → Check insert tightening torque
Parameter setting → Configure according to thickness-hole diameter matrix
Coolant activation → Pre-inject coolant for 30 seconds
Stepwise drilling → Retract every 5mm to clear chips and clean flutes
Ⅶ. Selection Recommendations and Scenario Adaptation
7.1 Drill Bit Selection
7.1.1.Material Options
Economical Type: Cobalt High-Speed Steel (M35)
Applicable scenarios: 304 stainless steel thin plates 2000 holes, TiAlN coating friction coefficient 0.3, reduces built-up edge by 80%, solves adhesion issues with 316L stainless steel.
Special Reinforced Solution (Extreme Conditions): Tungsten Carbide substrate + Nanotube coating
Nanoparticle reinforcement improves bending strength, heat resistance up to 1200°C, suitable for deep hole drilling (>25mm) or stainless steel with impurities.
7.1.2.Shank Compatibility
Domestic Magnetic Drills: Right-angle shank.
Imported Magnetic Drills (FEIN, Metabo): Universal shank, quick-change system supported, runout tolerance ≤ 0.01mm.
Japanese Magnetic Drills (Nitto): Universal shank only, right-angle shanks not compatible; require dedicated quick-change interface.
Machining Centers / Drilling Machines: HSK63 hydraulic tool holder (runout ≤ 0.01mm).
Handheld Drills / Portable Equipment: Four-hole quick-change shank with self-locking steel balls.
Special Adaptation: Conventional drill presses require Morse taper adapters (MT2/MT4) or BT40 adapters for compatibility with annular cutters.
7.2 Typical Scenario Solutions
7.2.1.Steel Structure Thin Plate Connection Holes
Pain Point: 3mm thick 304 stainless steel thin plates prone to deformation; roundness deviation > 0.2mm.
Solution:Drill bit: HSS right-angle shank (cutting depth 35mm) + magnetic drill with adsorption force > 23kN.
Parameters: Speed 450 rpm, feed 0.08 mm/rev, coolant: oil-water emulsion.
7.2.2.Shipbuilding Thick Plate Deep Hole Machining
Pain Point: 30mm thick 316L steel plates, traditional drill takes 20 minutes per hole.
Solution:
Drill bit: TiAlN coated carbide drill (cutting depth 100mm) + high-pressure cutting oil (ISO VG68).
Parameters: Speed 150 rpm, feed 0.20 mm/rev, stepwise chip evacuation.
7.2.3.Rail High Hardness Surface Hole Drilling
Pain Point: Surface hardness HRC 45–50, prone to edge chipping.
Solution:
Drill bit: Tungsten carbide four-hole shank drill + internal cooling channel (pressure ≥ 12 bar).
Assistance: V-type fixture clamping + laser positioning (±0.1mm accuracy).
7.2.4.Curved/Inclined Surface Positioning
Pain Point: Slippage on curved surface causes positioning error > 1mm.
Solution:
Three-step drilling method: Ø3mm pilot hole → Ø10mm expansion hole → target diameter drill bit.
Equipment: Magnetic drill integrated with cross laser positioning.
Ⅷ.Technical Value and Economic Benefits of Steel Plate Drilling
The core challenge of stainless steel drilling lies in the conflict between the material’s properties and traditional tooling. The annular cutter achieves a fundamental breakthrough through three major innovations:
Annular cutting revolution: removes only 12% of the material instead of full cross-section cutting.
Multi-edge mechanical load distribution: reduces load per cutting edge by 65%.
Dynamic cooling design: lowers cutting temperature by more than 300°C.
In practical industrial validations, annular cutters deliver significant benefits:
Efficiency: Single hole drilling time is reduced to 1/10 of that with twist drills, increasing daily output by 400%.
Cost: Insert life exceeds 2000 holes, reducing overall machining cost by 60%.
Quality: Hole diameter tolerance consistently meets IT9 grade, with near-zero scrap rates.
With the popularization of magnetic drills and advancements in carbide technology, annular cutters have become the irreplaceable solution for stainless steel processing. With correct selection and standardized operation, even extreme conditions such as deep holes, thin walls, and curved surfaces can achieve highly efficient and precise machining.
It is recommended that enterprises build a drilling parameter database based on their product structure to continuously optimize the entire tool lifecycle management.
Ⅰ. Introduction
Superalloys are metallic materials that maintain excellent strength, oxidation resistance, and corrosion resistance at high temperatures. They are widely used in aerospace engines, gas turbines, nuclear industries, and energy equipment. However, their superior properties pose significant challenges to machining. Especially when using end mills for milling operations, issues such as rapid tool wear, high cutting temperatures, and poor surface quality are particularly prominent. This article explores the common problems encountered when end milling superalloys and provides corresponding solutions.
Ⅱ. What is a Superalloy?
Superalloys (or high-temperature alloys) are metal materials that retain high strength and outstanding oxidation and corrosion resistance under elevated temperature environments. They can operate reliably under complex stress in oxidative and gaseous corrosion environments from 600°C to 1100°C. Superalloys mainly include nickel-based, cobalt-based, and iron-based alloys and are widely used in aerospace, gas turbines, nuclear power, automotive, and petrochemical industries.
Ⅲ. Characteristics of Superalloys
1.High Strength at Elevated Temperatures
Capable of withstanding high stress for extended periods at high temperatures without significant creep deformation.
2.Excellent Oxidation and Corrosion Resistance
Maintains structural stability even when exposed to air, combustion gases, or chemical media at elevated temperatures.
3.Good Fatigue and Fracture Toughness
Able to resist thermal cycling and impact loads in extreme environments.
4.Stable Microstructure
Exhibits good structural stability and resists degradation in performance during long-term high-temperature use.
Ⅳ. Typical Superalloy Materials
1.Nickel-Based Superalloys
Internationally Common Grades:
Grade
Features
Typical Applications
Inconel 718
Excellent high-temperature strength, good weldability
Aircraft engines, nuclear reactor components
Inconel 625
Strong corrosion resistance, resistant to seawater and chemicals
Marine equipment, chemical containers
Inconel X-750
Strong creep resistance, suitable for long-term high-temperature loads
Turbine parts, springs, fasteners
Waspaloy
Maintains high strength at 700–870°C
Gas turbine blades, sealing components
Rene 41
Superior high-temperature mechanical performance
Jet engine combustion chambers, tail nozzles
2.Cobalt-Based Superalloys
Internationally Common Grades:
Grade
Features
Applications
Stellite 6
Excellent wear and hot corrosion resistance
Valves, sealing surfaces, cutting tools
Haynes 188
Good oxidation and creep resistance at high temperatures
Turbine casings, combustion chamber parts
Mar-M509
Strong corrosion and thermal fatigue resistance
Hot-end components of gas turbines
Common Chinese Grades (with International Equivalents):
Grade
Features
Applications
K640
Equivalent to Stellite 6
Valve alloys, thermal equipment
GH605
Similar to Haynes 25
Manned space missions, industrial turbines
3.Iron-Based Superalloys
Features: Low cost, good machinability; suitable for medium-temperature environments (≤700°C).
Internationally Common Grades:
Grade
Features
Applications
A-286 (UNS S66286)
Good high-temperature strength and weldability
Aircraft engine fasteners, gas turbine components
Alloy 800H/800HT
Excellent structural stability and corrosion resistance
Heat exchangers, steam generators
310S Stainless Steel
Oxidation resistant, low cost
Furnace tubes, exhaust systems
Common Chinese Grades (with International Equivalents):
Grade
International Equivalent
Applications
1Cr18Ni9Ti
Similar to 304 stainless steel
General high-temperature environments
GH2132
Equivalent to A-286
Bolts, seals, springs
4.Comparison of Nickel-Based, Cobalt-Based, and Iron-Based Superalloys
Alloy Type
Operating Temperature Range
Strength
Corrosion Resistance
Cost
Typical Applications
Nickel-Based
≤1100°C
★★★★★
★★★★★
High
Aerospace, energy, nuclear power
Cobalt-Based
≤1000°C
★★★★
★★★★★
Relatively High
Chemical industry, gas turbines
Iron-Based
≤750°C
★★★
★★★
Low
General industry, structural parts
Ⅴ. Application Examples of Superalloys
Industry
Application Components
Aerospace
Turbine blades, combustion chambers, nozzles, sealing rings
Energy Equipment
Gas turbine blades, nuclear reactor components
Chemical Industry
High-temperature reactors, heat exchangers, corrosion-resistant pumps and valves
Oil Drilling
High-temperature and high-pressure seals, downhole tools
Automotive Industry
Turbocharger components, high-performance exhaust systems
Ⅵ. Challenges in Machining of Superalloys
1.High Strength and Hardness:
Superalloys maintain high strength even at room temperature(e.g.,the tensile strength of Inconel 718 exceeds 1000 MPa).During machining,they tend to form a work-hardened layer(with hardness increasing 2-3 times),which significantly increases the cutting resistance in subsequent operations.Under such conditions,tool wear is exacerbated,cutting forces fluctuate greatly,and chipping of the cutting edge is more likely to occur.
2.Poor Thermal Conductivity and Concentrated Cutting Heat:
Superalloys have a low thermal conductivity(e.g.,the thermal conductivity of Inconel 718 is only 11.4 W/m·K,about one-third of that of steel).The cutting heat cannot be dissipated quickly,and the cutting tip temperature can exceed 1000°C.This causes the tool material to soften(due to insufficient red hardness)and accelerates diffusion wear.
3.Severe Work Hardening:
The material surface becomes harder after machining,which further intensifies tool wear.
4.High Toughness and Difficulty in Chip Control:
The chips of superalloys are highly tough and do not break easily,often forming long chips that can wrap around the tool or scratch the workpiece surface.This affects the stability of the machining process and increases tool wear.
5.High Chemical Reactivity:
Nickel-based alloys are prone to diffusion reactions with tool materials(such as WC-Co cemented carbides),leading to adhesive wear.This causes the tool surface material to be worn away,forming a crescent-shaped wear crater.
Ⅶ. Common Issues in Milling Superalloys with End Mills
1. Severe Tool Wear
• The high hardness and strength of superalloys lead to rapid wear of the rake and flank faces of the end mill.
• High cutting temperatures can cause thermal fatigue cracks,plastic deformation,and diffusion wear in the tool.
2.Excessive Cutting Temperature
• The poor thermal conductivity of superalloys means that the large amount of heat generated during cutting cannot be dissipated in time.
• This leads to localized overheating of the tool,which can cause tool burnout or chipping in severe cases.
3.Severe Work Hardening
• Superalloys are prone to work hardening during machining,with surface hardness increasing rapidly.
• The next cutting pass encounters a harder surface,exacerbating tool wear and increasing cutting forces.
4.High Cutting Forces and Severe Vibration
• The high strength of the material results in large cutting forces.
• If the tool structure is not properly designed or if the tool is not securely clamped,it can lead to machining vibrations and chatter,causing tool damage or poor surface finish.
5.Tool Adhesion and Built-Up Edge
• At high temperatures,the material tends to adhere to the cutting edge of the tool,forming a built-up edge.
• This can cause unstable cutting,surface scratches on the workpiece,or inaccurate dimensions.
6.Poor Machined Surface Quality
• Common surface defects include burrs,scratches,surface hard spots,and discoloration in the heat-affected zone.
• High surface roughness can affect the service life of the part.
7.Short Tool Life and High Machining Costs
• The combined effect of the above issues results in a much shorter tool life compared to machining materials like aluminum alloy or low-carbon steel.
• Frequent tool replacement,low machining efficiency,and high machining costs are the consequences.8. Solutions & Optimization
Ⅷ. Solutions and Optimization Recommendations
1.Solutions for Severe Tool Wear:
1.1.Choose ultrafine grain carbide material(Submicron/Ultrafine grain Carbide),which offers superior wear resistance and transverse rupture strength.
*Ultrafine grain cemented carbide is widely used in molds, cutting tools, precision machining, electronic components, and other fields due to its excellent wear resistance and high hardness. The typical WC grain size ranges from approximately 0.2 to 0.6 μm. According to standards from different countries and brands, the commonly used grades of ultrafine grain cemented carbide are as follows:
A.China Common Ultrafine Grain Cemented Carbide Grades (e.g. XTC, Zhuzhou Cemented Carbide, Jiangxi Rare Earth, Meirgute, etc.)
Grade
Grain Size (μm)
Co Content (%)
Features & Applications
YG6X
0.6
6.0
Suitable for high-precision and high-hardness applications; ideal for finishing hard materials.
YG8X
0.6
8.0
Slightly better flexural strength and toughness than YG6X; suitable for tools such as milling cutters and drills.
YG10X
0.6
10.0
Excellent overall performance; suitable for applications requiring both wear resistance and toughness.
ZK10UF
~0.5
10.0
Zhuzhou carbide grade, used for micro drills, PCB drills, and other precision tools.
TF08
0.5
8.0
Meirgute ultrafine grade, suitable for machining titanium alloys and difficult-to-cut metals.
WF25
0.5
12.0
Specifically optimized for machining titanium alloys and stainless steel, with strong chipping resistance.
B.German Grades (e.g. CERATIZIT, H.C. Starck, etc.)
Grade
Grain Size (μm)
Co Content (%)
Features & Applications
CTU08A
0.4
8.0
Ultra-high hardness,suitable for high-speed precision machining.
K40UF
0.5
10.0
High wear resistance; ideal for dry cutting and aluminum machining.
S10
0.5
10.0
Suitable for hard materials and ceramic machining.
C.Japanese Grades (e.g. Mitsubishi, Sumitomo, Toshiba, etc.)
Grade
Grain Size (μm)
Co Content (%)
Features & Applications
UF10
0.4-0.6
10.0
Sumitomo’s commonly used ultrafine grade, suitable for precision end mills.
TF20
0.5
12.0
Mitsubishi’s high-toughness ultrafine grade, used for milling difficult-to-machine materials.
SF10
0.5
10.0
Used for small-diameter drills, PCB tools, etc.
D. USA Grades(Kennametal、Carbide USA)
Grade
Grain Size (μm)
Co Content (%)
Features & Applications
K313
0.4
6.0
High hardness, low Co content, suitable for hard material machining.
KD10F
0.6
10.0
General-purpose ultrafine grade with excellent wear resistance.
GU10F
0.4-0.5
10.0
Used in applications requiring high surface quality.
1.2.Optimize tool geometry,such as reducing the rake angle and maintaining a moderate clearance angle,to enhance edge strength.
1.3. Perform edge honing to prevent chipping and the propagation of microcracks.
2.Solutions for Excessive Cutting Temperature:
2.1 Use high-performance heat-resistant coatings,such as AlTiN,SiAlN,or nACo,capable of withstanding cutting temperatures of 800–1000°C.
2.2 Implement high-pressure cooling systems(HPC)or minimum quantity lubrication(MQL)to remove cutting heat promptly.
2.3 Reduce cutting speed(Vc)to minimize heat generation.
3.Solutions for Severe Work Hardening:
3.1 Increase the feed per tooth(fz)to reduce the dwell time of the tool in the work-hardened layer.
3.2 Opt for smaller depths of cut(ap)and multiple passes to remove the hardened layer incrementally.
3.3 Keep the tool sharp to avoid cutting with a dull edge through the hardened layer.
4.Solutions for High Cutting Forces and Severe Vibration:
4.1Use variable helix and variable pitch tools(unequal spacing)to reduce resonance.
4.2 Minimize tool overhang length(keep L/D ratio
1. WHAT IS THE CARBIDE BURR?
Carbide burr, also known as burr bit, burr cutter, carbide burr bit, carbide die grinder bit etc. Strictly speaking, the carbide burr is a kind of rotary cutting tool which is clamped on pneumatic tools or power tools and specially used to remove metal burr, welding scar, weld cleaning. It is mainly used in the rough machining process of the workpiece with high efficiency.
2. THE COMPONENT OF CARBIDE BURR?
Carbide burr can be divided into brazed type and solid type. The brazed type is made of carbide head part and steel shank part brazed together, when the diameter of burr head and shank are not same, the brazed type is used. The solid type is made of solid carbide when the diameter of burr head and shank are same.
3. WHAT IS CARBIDE BURR USED FOR?
Carbide burr have been widely used, it is an important way to improve production efficiency and achieve the mechanization of fitter. In recent years, with the increasing number of users, it has become a necessary tool for fitter and repairman.
The main uses:
♦ chip removing.
♦ shape modification.
♦ edge and chamfer finish.
♦ perform preparatory milling for build up welding.
♦ weld cleaning.
♦ clean casting materials.
♦ improve the geometry of the workpiece.
The main industries:
♦ Mold industry. For finishing all kinds of metal mold cavity, such as shoe mold and so on.
♦ Engraving industry. For engraving all kinds of metal and non-metal, such as craft gift.
♦ Equipment manufacturing industry. For cleaning the fin, burr, welding-seam of casting, forge piece and weldment, such as casting machine factory, shipyard, wheel hub polishing in automotive factory, etc.
♦ Machinery industry. For processing the chamfer, round, groove and keyway of all kinds of mechanical parts, cleaning pipes, finishing the surface of the inner hole of the machine parts, such as machinery factory, repair shop and so on.
♦ Engine industry. For sleeking the flow pass of impeller, such as car engine factory.
♦ Welding industry. For sleeking the welding surface, such as riveting welding.
4. THE ADVANTAGES OF CARBIDE BURR.
♦ All kinds of metals (including hquenched steel) and non-metallic materials (such as marble, jade, bone, plastic) with hardness below HRC70 can be cut arbitrarily by carbide burr.
♦ It can replace small grinding wheel with shank in most work, and no dust pollution.
♦ High production efficiency, tens of times higher than the processing efficiency of manual file, and more than ten times higher than the processing efficiency of small grinding wheel with shank.
♦ With good processing quality, high surface finish, carbide burr can process various shapes of mold cavity with high precision.
♦ Carbide burr there is a long service life, 10 times more durable than high speed steel cutter, and 200 times durable more than aluminum oxide grinding wheel.
♦ Carbide burr is easy to use, safe and reliable, it can reduce labor intensity and improve the working environment.
♦ The economic benefit after use carbide burr is greatly improved, and the comprehensive processing cost can be reduced tens of times by use carbide burr.
5. THE RANGE OF MACHINED MATERIALS OF CARBIDE BURR.
Application
Materials
Used for deburring, milling of preparation process, surfacing welding, welding spot machining, forming machining, casting chamfering, sinking machining, cleaning.
Steel, Cast Steel
Not hard steel, not heat treated steel, strength not exceeding 1.200N/mm²(38HRC)
tool steel, tempered steel, alloy steel, cast steel
Stainless Steel
Rust proof and acid proof steel
austenitic and ferritic stainless steels
Nonferrous Metals
soft nonferrous metals
aluminum
brass, red copper, zinc
hard nonferrous metal
aluminum alloy, brass, copper, zinc
brass, titanium/titanium alloy, duralumin alloy (high silicon content)
heat-resisting material
Nickel base and cobalt base alloys (engine and turbine manufacturing)
Cast Iiron
grey cast iron, white cast iron
nodular graphite / ductile iron EN-GJS(GGG)
white annealed cast iron EN-GJMW(GTW),
black iron EN-GJMB(GTS)
Used for milling, forming processing
Plastic, Other Materials
fiber reinforced plastics (GRP/CRP), fiber content ≤40%
fiber reinforced plastics (GRP/CRP), fiber content >40%
Used for trimming,form milling of cutting hole
thermoplastic
6. THE MATCHING TOOLS OF CARBIDE BURR.
Carbide burr are usually used with high speed electric grinder or pneumatic tools, it also can be used by mounted on machine tools. Because of pneumatic tools are commonly used in industry, so the use of carbide burr in industry is generally driven by pneumatic tools. For personal use, electric grinder is more convenient, it works after you plug it in, without air compressor. All you need to do is choose a electric grinder with high speed. The recommended speed is generally 6000-40000 RPM, and a more detailed description of the recommended speed is given following.
7. THE RECOMMENDED SPEED OF CARBIDE BURR.
Carbide burr should be operated at a reasonable speed of 1,500 to 3,000 surface feet per minute. According to this specification, a wide variety of carbide burr are available for grinders. For example: 30,000-RPM grinders can match carbide burr whose diameters is 3/16" to 3/8" ; For 22,000- RPM grinders, 1/4" to 1/2" diameter carbide burr are available. However, for more efficient operation, it is best to choose the most commonly used diameter.
In addition, the optimization of grinding environment and the maintenance of grinding machine are also very important. If a 22,000-rpm grinder go wrong frequently, probably because the RPM is too low. Therefore, we recommend that you should often check the air pressure system and seal assembly of your grinding machine.
A reasonable working speed is indeed very important to achieve a good cutting effect and work piece quality. Increasing the speed can improve the processing quality and extend the tool life, but if the speed is too high may cause the steel shank to crack; Reducing the speed is helpful for fast cutting, however, it may cause system overheating and reduce cutting quality. So each type of carbide burr should be chose according to the specific operation of the appropriate speed.
Please check the recommended speed list as below:
The recommended speed list for carbide burr use.
The speed range is recommended for different materials and burr diameters
(rpm)
Burr Diameters
3mm (1/8")
6mm (1/4")
10mm (3/8")
12mm (1/2")
16mm (5/8")
Maximum Operating Speed (rpm)
90000
65000
55000
35000
25000
Aluminum, Plastic
Speed range
60000-80000
15000-60000
10000-50000
7000-30000
6000-20000
Recommended starting speed
65000
40000
25000
20000
15000
Copper, Cast Iron
Speed range
45000-80000
22500-60000
15000-40000
11000-30000
9000-20000
Recommended starting speed
65000
45000
30000
25000
20000
Mild Steel
Speed range
60000-80000
45000-60000
30000-40000
22500-30000
18000-20000
Recommended starting speed
80000
50000
30000
25000
20000
Grinding teeth on carbide end mills is a highly specialized process that involves several steps to ensure the tools achieve the desired cutting performance. Here is a detailed overview of the process:
1. Material Selection
Carbide end mills are typically made from solid carbide rods, primarily composed of tungsten carbide with binders like cobalt or nickel to enhance toughness. The quality and composition of the material are crucial for the tool's performance.
2. Preparation of Carbide Rods
The selected carbide rods are cut to the required lengths using precision cutting tools or machinery. This step ensures that the raw material is ready for further processing.
3.Grinding the Flutes
The flute grinding process is where the cutting edges of the end mill are formed. Specialized grinding machines, often equipped with diamond or CBN wheels, are used to grind the flutes into the carbide rod. The number, shape, and geometry of the flutes depend on the specific design and application of the end mill. For example:
• Straight Flutes:Suitable for roughing operations and cutting softer materials.
• Helical Flutes:Provide better chip evacuation and reduced cutting forces, making them ideal for finishing operations.
• Variable Flutes:Offer improved vibration resistance and smoother cuts, especially in high-speed machining.
4.Grinding the Shank
The shank of the end mill, which is the part that fits into the machine tool, is ground to the appropriate diameter and length. This step ensures that the end mill can be securely held and accurately positioned during machining operations.
5.Heat Treatment
After grinding, the carbide end mills undergo heat treatment, typically through a process called sintering. This involves heating the tools to high temperatures in a controlled atmosphere furnace, which helps bond the carbide particles and enhances the tool's hardness and toughness.
6.Final Grinding of Cutting Edges
The cutting edges are then ground to achieve the required geometry. This step ensures that the edges are sharp and precise, which is essential for effective machining.
7. Quality Control and Inspection
Throughout the manufacturing process,strict quality control measures are implemented. This includes inspecting the end mills for dimensional accuracy, flute geometry, surface finish, and hardness. Any deviations from the specified parameters are corrected to ensure the tools meet high-quality standards.
8.Coating and Packaging
Some carbide end mills may undergo additional surface treatments,such as coating with specialized materials to enhance wear resistance and performance. Finally, the tools are packaged and prepared for distribution.
Grinding teeth on carbide end mills is a complex process that requires precision, specialized equipment, and advanced techniques. By following these steps, manufacturers can produce high-quality tools that meet the demanding requirements of modern machining applications.
When choosing between TiAlSiN (Titanium Aluminum Silicon Nitride), TiAlSiNX (Titanium Aluminum Silicon Nitride with added X-element), and AlTiN (Aluminum Titanium Nitride) for end mills, it’s important to evaluate the material you are machining, the cutting conditions (such as speed, feed, and temperature), and the overall desired performance in terms of tool life, wear resistance, and oxidation resistance.
Let’s break down the characteristics of each coating to help you decide which is best for your application:
1. TiAlSiN (Titanium Aluminum Silicon Nitride)
Properties:
Heat Resistance: TiAlSiN is known for excellent heat resistance, withstanding temperatures up to 1,000°C (1,832°F). This makes it suitable for high-speed and high-temperature machining.
Wear Resistance: It provides good wear resistance, especially in high-stress, high-temperature environments.
Silicon Content: The addition of silicon helps to reduce friction and wear, while also improving the coating’s ability to resist oxidation at elevated temperatures.
Hardness: TiAlSiN coatings have high hardness, which contributes to their ability to maintain sharpness and cutting edge integrity under heavy-duty cutting conditions.
Best For:
High-Temperature Machining: TiAlSiN is ideal for machining hard-to-cut materials like high-strength steels, stainless steels, and titanium alloys.
Aerospace and Automotive: It's commonly used in aerospace and automotive applications, where heat and wear are major concerns.
Heavy-Duty Cutting: Suitable for cutting operations that involve high cutting forces and heat, including high-speed machining and roughing operations.
Advantages:
Excellent heat resistance, which prevents tool failure at high temperatures.
Reduced friction, leading to smoother cutting and improved surface finishes.
Good resistance to oxidation and wear.
Applications:
High-performance machining of difficult materials such as titanium alloys, superalloys (like Inconel), and hardened steels.
Heavy-duty cutting operations, including rough milling, where heat buildup is significant.
2. TiAlSiNX (Titanium Aluminum Silicon Nitride with added X-element)
Properties:
Enhanced Heat and Wear Resistance: TiAlSiNX is an advanced version of TiAlSiN, with the "X" element (typically an addition like carbon, nitrogen, or another element) that further enhances wear resistance and oxidation resistance at even higher temperatures. This makes it ideal for extreme high-speed cutting.
Improved Surface Properties: The addition of the "X" element generally improves the coating’s surface properties, reducing friction and improving chip flow during machining, which enhances overall cutting efficiency.
Temperature Resistance: TiAlSiNX can handle cutting temperatures even higher than TiAlSiN (up to 1,100°C to 1,200°C or 2,012°F to 2,192°F), making it excellent for the most demanding applications.
Best For:
Extreme High-Temperature Machining: TiAlSiNX is ideal for applications where extremely high temperatures are encountered, such as in superalloys, titanium, high-speed steels, and aerospace materials.
Superalloys and High-Temperature Alloys: TiAlSiNX excels in cutting difficult materials that generate intense heat and require extreme heat resistance.
High-Speed Precision Cutting: Suitable for high-precision applications where high cutting speeds and extreme temperatures are present.
Advantages:
Superior oxidation resistance at very high temperatures.
Higher hardness and wear resistance compared to TiAlSiN.
Excellent for high-speed milling in challenging materials.
Reduced friction for smoother cuts and better surface finishes.
Applications:
Aerospace, automotive, and power generation industries where materials such as Inconel, titanium, and high-temperature alloys are commonly used.
Precision cutting at extreme cutting speeds and high temperatures.
3. AlTiN (Aluminum Titanium Nitride)
Properties:
Heat Resistance: AlTiN has good heat resistance, typically up to 900°C (1,650°F). While it does not handle heat as well as TiAlSiN or TiAlSiNX, it is still effective in moderate to high-temperature machining.
Wear Resistance: It is known for its good wear resistance and hardness, making it suitable for general-purpose machining applications.
Friction Reduction: AlTiN reduces friction between the cutting tool and the material, leading to improved chip flow and a longer tool life.
Best For:
General-Purpose Machining: AlTiN is a solid all-rounder for machining a wide variety of materials, including carbon steels, alloy steels, and stainless steels.
Moderate-Speed Cutting: Suitable for high-speed milling but not as ideal for the most extreme temperatures encountered in superalloy and titanium machining.
Applications That Don’t Require Extreme Heat Resistance: AlTiN is perfect for applications where heat is present, but not to the levels where TiAlSiN or TiAlSiNX would be required.
Advantages:
Excellent general wear resistance and good oxidation resistance.
Cost-effective for moderate cutting speeds and temperatures.
Performs well with most materials, offering good tool life.
Applications:
General machining of steels, stainless steels, and light alloy materials.
Suitable for high-speed steel machining but not extreme high-heat or high-performance environments.
Choosing the Right Coating
1. Material Type and Hardness
TiAlSiN: Best for machining high-temperature alloys, stainless steels, titanium, and hard materials. Ideal for general high-performance cutting.
TiAlSiNX: Ideal for superalloys, Inconel, and other high-strength, heat-resistant materials. Best for extreme cutting conditions at high temperatures.
AlTiN: Great for general-purpose applications with moderate heat generation, including carbon steels and non-ferrous metals.
2. Cutting Conditions (Speed, Feed, Depth)
TiAlSiN: Works well for high-speed and heavy-duty cutting in medium to high-temperature environments.
TiAlSiNX: Best suited for extreme high-speed cutting with high cutting temperatures, where tool life and wear resistance are critical.
AlTiN: Suitable for moderate-speed cutting with medium heat generation and general-purpose operations.
3. Tool Life Expectations
TiAlSiNX: Offers the longest tool life in extreme, high-speed, high-temperature operations.
TiAlSiN: Offers excellent wear resistance in high-performance cutting, but not as durable at extreme heat conditions as TiAlSiNX.
AlTiN: Good tool life for general-purpose machining but might wear out faster in high-temperature or heavy-duty applications compared to TiAlSiN or TiAlSiNX.
4. Cost Considerations
TiAlSiNX is the most expensive of the three due to its advanced formulation and superior performance at extreme temperatures.
TiAlSiN offers a great balance of performance and cost for high-performance applications.
AlTiN is more affordable and works well for many general-purpose cutting applications.
Summary Table:
Coating Type
Best For
Key Advantages
Applications
TiAlSiN
High-temperature alloys, high-speed cutting
Excellent heat resistance, wear resistance, suitable for high-performance cutting
Aerospace, automotive, hardened steels, titanium alloys
TiAlSiNX
Superalloys, Inconel, aerospace, extreme conditions
Superior oxidation resistance, handles higher temperatures, reduced friction
Extreme high-speed machining, aerospace, superalloys
AlTiN
General-purpose machining, steels, stainless steels
Good heat resistance, wear resistance, cost-effective
Carbon steel, alloy steels, stainless steel machining
Conclusion:
Use TiAlSiN for general high-performance machining of tough materials and alloys that experience significant heat during cutting.
Use TiAlSiNX for extreme high-speed cutting, especially with superalloys, titanium, and aerospace materials, where heat resistance and wear resistance are crucial.
Use AlTiN for general machining where heat generation is moderate, such as carbon steels, stainless steels, and non-ferrous metals.
By matching the coating to your specific machining needs, you can maximize both tool life and performance.