solutions

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

The brazing technology and brazing material selection directly determine the quality level of carbide burr. The majority of domestic manufacturers, even some manufacturers in other countries, they use copper brazing with a hole of carbide blanks. Although the carbide burr made in this way is more cheap, because it saves on tungsten carbide raw materials and welding material is the cheapest, but the carbide burr produced in this way is of poor quality and very unstable, because there are two key issues involved, one is welding temperature and another is welding stress control.   Firstly, use Sandwich type silver welding material, the temperature required for Sandwich type silver welding material is around 800°C, the temperature required for copper brazing material is around 1100°C. According to relevant research reports and our experience, when the temperature exceeds about 900°C, the surface of cemented carbide begins to oxidize rapidly, the cobalt in carbide burrs tends to liquefy, and the metallographic structure of cemented carbide begins to change. So, in the process of copper brazing, the properties of carbide burr there will be a degree of damaged, but in the process of Sandwich type silver welding, the damage to the properties of carbide burr is very limited, it's almost negligible. Then, the design of Sandwich type silver welding sheet, its two ends of the welding sheet are silver and the interlayer is copper alloy, this kind of welding material can significantly reduce the welding stress, it do not cause micro cracks in the carbide burrs, at the same time, its welding strength is much higher. Finally, use the automatic welding machine is also a very important factor, in the automatic welding process, the carbide cutting head and steel shank are automatic butt-jointed, no human involvement, so its stability and uniformity is much better than human manual welding.

When selecting the right grades of Cemented Carbide Bars, it’s essential to understand that YG grades are typically used to categorize tungsten carbide grades that contain cobalt as the binder material. The “YG” designation refers to Y being for carbide material and G indicating cobalt as the binder. The numerical value after “YG” generally represents the cobalt content in the material. Tungsten carbide grades in the YG series are designed to provide a balance of hardness and toughness, with the cobalt content affecting the toughness and the carbide content impacting the hardness and wear resistance.     Let’s explore how to choose the right YG tungsten carbide grade for your specific application, based on its key properties and typical uses: 1. Understand the YG Series Designation The YG grades are differentiated based on their cobalt content and, to a lesser degree, the grain size of the carbide. Common YG grades include: YG6: 6% cobalt content YG8: 8% cobalt content YG10: 10% cobalt content YG15: 15% cobalt content YG20: 20% cobalt content Generally: Higher cobalt content increases toughness and impact resistance, but reduces wear resistance. Lower cobalt content increases hardness and wear resistance, but reduces toughness. 2. Key Properties to Consider When Choosing YG Grades 1. Hardness vs. Toughness Hardness: Higher tungsten carbide content (and lower cobalt content) provides better wear resistance, which is critical for cutting tools, wear-resistant parts, and abrasion-heavy applications. Toughness: Higher cobalt content enhances the toughness, making the material more resistant to cracking and chipping under impact or vibration. 2. Wear Resistance vs. Impact Resistance Wear Resistance: Tungsten carbide with a higher carbide content (less cobalt) is more wear-resistant. These grades are typically used for cutting tools and components exposed to abrasive environments. Impact Resistance: Tungsten carbide with higher cobalt content is more impact-resistant. These grades are more suitable for heavy-duty applications like mining tools or heavy machinery. 3. Grain Size Fine Grain Size: Fine-grain carbide has better hardness and wear resistance but lower toughness. It's used in applications like high-precision cutting tools. Coarse Grain Size: Coarse-grain carbide offers higher toughness but lower hardness. It's used in applications that require resistance to impact and fatigue, such as mining tools. 3. Choosing the Right YG Grade Based on Application 1. Cutting Tools (Milling, Drilling, Turning, etc.) Recommended Grade: YG6 to YG8 (Low cobalt content, higher tungsten carbide content) Properties Needed: Hardness, wear resistance, and precision. Use Case: For high-speed machining of materials like steel, stainless steel, and non-ferrous materials. These grades are excellent for applications where wear resistance is essential, and toughness requirements are moderate. Example: YG6 (fine grain) would be used for cutting tools requiring high hardness and wear resistance. 2. Heavy Wear Applications (Mining, Earthmoving, etc.) Recommended Grade: YG10 to YG15 (Moderate to high cobalt content, with a good balance of toughness and wear resistance) Properties Needed: Impact resistance, toughness, and abrasion resistance. Use Case: For mining tools, drill bits, and rock crushers, where the material is exposed to high levels of impact and abrasion. Example: YG15 (coarser grain and higher cobalt content) would be used in mining and construction tools to withstand heavy impact and abrasive conditions. 3. High-Impact, Fatigue-Prone Applications Recommended Grade: YG15 to YG20 (Higher cobalt content for better toughness) Properties Needed: Toughness, resistance to cracking, and vibration resistance. Use Case: For tools exposed to heavy impact or vibration (e.g., hammering tools, grinding media). Example: YG20 (coarse grain, high cobalt content) is ideal for heavy-duty applications like rock drills, impact hammers, or machinery exposed to vibration. 4. Precision Molds, Dies, and Tools Recommended Grade: YG6 to YG8 (Fine-grain, low cobalt content) Properties Needed: High hardness, sharp edges, and wear resistance. Use Case: For precision molding, stamping, and cutting tools that require sharpness and excellent wear resistance in high-precision machining of softer metals and plastics. Example: YG6 would be optimal for fine-grain cutting tools that need to maintain sharp edges for precise work. 5. Forming Tools and Dies (Stamping, Forging, etc.) Recommended Grade: YG8 to YG10 (Balanced hardness and toughness) Properties Needed: Good toughness to resist chipping and wear resistance for longevity. Use Case: For forging dies, extrusion dies, and forming tools that experience both high wear and impact. Example: YG10 would work well for dies used in forming and extrusion processes that require a balance of impact resistance and wear resistance. 4. Summary Table for YG Grades Grade Cobalt Content (%) Hardness Toughness Application Properties YG6 6% High Low Precision cutting tools, molds High wear resistance, fine grain YG8 8% High Moderate Drills, cutting tools, dies Good balance of wear resistance and toughness YG10 10% Moderate High Forming tools, heavy cutting tools Good toughness, suitable for tougher materials YG15 15% Low Very High Mining tools, impact tools High impact resistance, good for high-stress applications YG20 20% Low Very High Heavy-duty machinery, hammers Maximum toughness, suited for high-impact conditions 5. Factors to Consider When Choosing the Right YG Grade Application Type: Will the tool be exposed to high impact, high wear, or precision cutting? If impact resistance is more critical, a grade with higher cobalt content (YG10, YG15, YG20) should be chosen. For wear resistance, a lower cobalt grade (YG6, YG8) is ideal. Material to be Machined: Consider the hardness of the material being machined. Softer materials require tools with higher wear resistance, while harder materials demand toughness to prevent chipping. Work Environment: Applications exposed to extreme temperatures, vibrations, or harsh conditions might require higher cobalt content for added toughness (YG15, YG20). Tool Life Expectancy: For tools that need to last longer under heavy wear conditions, consider higher tungsten content (lower cobalt). Conclusion Choosing the right YG tungsten carbide grade depends on the specific requirements of your application, including factors like hardness, toughness, wear resistance, and impact resistance. YG6 and YG8 are ideal for precision cutting and general machining. YG10 and YG15 provide a balance of wear resistance and toughness for mining tools, cutting tools, and forming dies. YG20 is best suited for high-impact applications, offering the greatest toughness. Understanding the trade-off between wear resistance and toughness will help you select the most suitable YG grade for your specific needs. 4o

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.

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