Carpenter,Speed Star® High Speed Steel Rod/Bar (Red-Hard) (AISI M2)

Carpenter Speed Star® High Speed Steel Rod (Red-Hard) (AISI M2) Product Information -:- For detailed product information, please contact sales. -: Carpenter Speed Star® High Speed Steel Rod (Red-Hard) (AISI M2) Synonyms -:- For detailed product information, please contact sales. -:

Carpenter Speed Star® High Speed Steel (Red-Hard) (AISI M2) Product Information -:- For detailed product information, please contact sales. -: # **Carpenter Speed Star® High Speed Steel (Red-Hard) (AISI M2)** ## **Premium Tungsten-Molybdenum High Speed Steel for Superior Cutting Performance and Red-Hardness** --- ### **Product Overview** Carpenter Speed Star® is a premium tungsten-molybdenum high speed steel (HSS) corresponding to the AISI M2 classification, renowned as the industry workhorse for high-performance cutting tools. Engineered to deliver **exceptional red-hardness, high wear resistance, and good toughness**, this alloy maintains cutting edge integrity at elevated temperatures up to 600°C (1112°F). Characterized by its balanced chemistry of tungsten, molybdenum, vanadium, and chromium, Speed Star provides an optimal combination of properties for a wide range of metal cutting applications where heat generation and abrasion challenge tool life. Its versatility and proven performance have established it as the most widely used high speed steel globally. --- ### **Key Advantages** - **Excellent Red-Hardness**: Maintains cutting hardness at elevated temperatures up to 600°C (1112°F) - **High Wear Resistance**: Vanadium and tungsten carbides provide exceptional abrasion resistance - **Good Toughness**: Balanced chemistry offers better impact resistance than higher-alloy HSS grades - **Versatile Performance**: Suitable for a broad range of machining operations and materials - **Cost-Effective HSS Solution**: Premium performance at reasonable cost compared to cobalt grades - **Good Grindability**: Better than higher-vanadium or cobalt-containing HSS grades - **Reliable Heat Treatment Response**: Forgiving hardening characteristics with wide processing windows - **Wide Availability**: Readily available in multiple forms and sizes --- ### **Chemical Composition (%)** | Element | Carbon (C) | Tungsten (W) | Molybdenum (Mo) | Chromium (Cr) | Vanadium (V) | Cobalt (Co) | |---------|------------|--------------|-----------------|---------------|--------------|-------------| | **Content** | 0.78-0.88 | 5.50-6.75 | 4.50-5.50 | 3.75-4.50 | 1.75-2.20 | ≤0.50 | *Additional Elements:* - Silicon (Si): 0.20-0.45% - Manganese (Mn): 0.15-0.40% - Phosphorus (P): ≤0.030% - Sulfur (S): ≤0.030% - Nickel (Ni): ≤0.30% - Copper (Cu): ≤0.25% *Note: The balanced tungsten-molybdenum ratio (approximately 1:1) provides optimal secondary hardening response and cost-effectiveness, while vanadium content ensures good wear resistance through hard MC-type carbides.* --- ### **Physical & Mechanical Properties** #### **Physical Properties** - **Density**: 8.16 g/cm³ (0.295 lb/in³) - **Melting Point**: 1420-1460°C (2590-2660°F) - **Thermal Conductivity**: 23.0 W/m·K at 20°C - **Coefficient of Thermal Expansion**: 11.0 × 10⁻⁶/°C (20-100°C) - **Modulus of Elasticity**: 215 GPa (31.2 × 10⁶ psi) - **Specific Heat**: 460 J/kg·K at 20°C - **Electrical Resistivity**: 0.38 μΩ·m at 20°C #### **Mechanical Properties** **Annealed Condition (typical):** - Hardness: 200-240 HB - Ultimate Tensile Strength: 690-830 MPa (100-120 ksi) - Yield Strength: 415-550 MPa (60-80 ksi) - Elongation: 12-18% - Reduction of Area: 30-40% - Machinability Rating: 40% (relative to 1% carbon steel, 100%) **Hardened and Tempered Condition:** - **Typical Hardness Range**: **63-66 HRC** (optimal 64-65 HRC for most applications) - Ultimate Tensile Strength: 2200-2500 MPa (319-363 ksi) - Yield Strength: 1900-2200 MPa (276-319 ksi) - Elongation: 3-5% - Reduction of Area: 10-15% - **Impact Toughness (Charpy V-notch)**: 12-18 J (9-13 ft-lb) at 65 HRC - **Compressive Strength**: 3000-3400 MPa (435-493 ksi) - Transverse Rupture Strength: 3500-4000 MPa (508-580 ksi) - **Red-Hardness**: Maintains 60 HRC at 600°C (1112°F) - **Hot Hardness at 600°C**: 800-850 HV **Hardenability Characteristics:** - Fully hardenable in air or oil up to 75mm (3 inches) diameter - Surface hardness of 65-67 HRC achievable on proper hardening - Through-hardness typically 1-2 HRC points lower than surface - Dimensional change: typically +0.10% to +0.20% on hardening - Good resistance to decarburization during heat treatment #### **Heat Treatment Parameters** 1. **Annealing:** - Temperature: 850-870°C (1560-1600°F) - Cooling: Slow furnace cool to 540°C (1000°F) at 15°C (25°F)/hour, then air cool - Resulting hardness: 200-240 HB - *For spheroidized structure: Hold at 790-815°C (1450-1500°F) for extended time* 2. **Stress Relieving (after rough machining):** - Temperature: 650-675°C (1200-1250°F) for 1-2 hours - Air cool 3. **Preheating (CRITICAL):** - First stage: 550-650°C (1025-1200°F) - Second stage: 800-850°C (1475-1560°F) - Soak time: 30-60 minutes per inch of thickness 4. **Austenitizing:** - Temperature: **1190-1220°C (2175-2230°F)** - Soak time: 2-4 minutes per 25mm (1 inch) of thickness - *Critical: Precise temperature control essential (±5°C recommended)* - Protective atmosphere or salt bath recommended 5. **Quenching:** - Medium: Oil quenching for maximum hardness - Alternative: Salt bath or high-pressure gas quenching for minimal distortion - Cooling rate: Rapid cooling to 540°C (1000°F), then slower to room temperature - Cool to 50-70°C (120-160°F) before tempering 6. **Tempering:** - **Double or triple tempering MANDATORY** - Temperature: **540-580°C (1000-1075°F)** - Duration: 1-2 hours per temper, minimum 2 hours each - Between tempers: Cool to room temperature - Typical tempering response: - First temper: 63-65 HRC - Second temper: 64-66 HRC (increase due to secondary hardening) - Third temper: 64-66 HRC (stabilization) - *Note: Maximum hardness occurs after second temper due to secondary hardening* --- ### **International Standards & Cross-References** | Standard System | Designation | Notes | |----------------|-------------|-------| | **Carpenter** | Speed Star® | Proprietary name for premium M2 steel | | **AISI** | M2 | Standard tungsten-molybdenum high speed steel | | **UNS** | T11302 | Unified Numbering System | | **ISO** | HS6-5-2 | ISO 4957 designation | | **European (EN)** | 1.3343 | High speed steel designation | | **German (DIN)** | 1.3343 | Standard designation | | **British (BS)** | BM2 | British specification | | **Japanese (JIS)** | SKH51 | Equivalent HSS grade | | **French (AFNOR)** | HS6-5-2 | French equivalent | | **Swedish (SS)** | 2722 | Swedish standard | | **Common Equivalents** | HS 6-5-2, Z85WDCV 06-05-04-02 | Commercial equivalents | --- ### **Typical Applications** #### **1. Metal Cutting Tools** - **Drills**: Twist drills, step drills, core drills for steel, cast iron, and non-ferrous metals - **End Mills**: Solid and indexable end mills for milling operations - **Turning Tools**: Single-point lathe tools and inserts - **Threading Tools**: Taps, dies, and thread mills - **Reamers**: Precision hole finishing tools - **Broaches**: Internal and surface broaches - **Gear Cutters**: Hobs, shapers, and shaving cutters - **Saw Blades**: Band saw and circular saw blades for metal cutting #### **2. Forming and Stamping Tools** - **Cold Work Punches and Dies**: For high-volume stamping operations - **Shear Blades**: For cutting metal sheets and plates - **Forming Rolls**: For roll forming operations - **Extrusion Dies**: For non-ferrous metal extrusion #### **3. Plastic and Rubber Processing** - **Injection Mold Components**: Cavities and cores for abrasive plastics - **Extrusion Screws and Barrels**: For filled plastic compounds - **Cutting Blades**: For plastic and rubber trimming #### **4. Woodworking Tools** - **Router Bits**: For hardwoods and composite materials - **Planer Knives**: For abrasive wood species - **Saw Blades**: For cutting engineered wood products #### **5. Specialized Industrial Tools** - **Knives and Blades**: For paper, textile, and food processing - **Wear Parts**: For moderate temperature abrasive applications - **Machine Components**: Where wear resistance and hardness are required --- ### **Machining & Fabrication Guidelines** #### **In Annealed Condition (200-240 HB)** - **Machinability**: Fair to poor (40% of 1% carbon steel) - **Recommended Cutting Tools**: Carbide tools strongly recommended - **Turning Speeds**: 25-40 SFM with carbide, 10-20 SFM with HSS - **Milling Speeds**: 20-35 SFM with carbide - **Drilling Speeds**: 15-25 SFM with carbide drills - **Coolant**: Essential for extended tool life and chip control - **Chip Characteristics**: Produces short, abrasive chips; use positive rake carbide tools #### **Grinding and Finishing** - **Hardened State Grinding**: Requires careful technique - **Wheel Selection**: Use aluminum oxide (32A-46H-V) or CBN wheels - **Grinding Parameters**: Light passes with ample coolant to prevent overheating - **Surface Finish**: Capable of achieving excellent finishes with proper technique - **Electrical Discharge Machining (EDM)**: Suitable; requires post-EDM stress relief --- ### **Surface Treatment Compatibility** #### **Recommended Coatings** - **PVD Coatings**: TiN, TiCN, TiAlN, AlCrN for enhanced performance - **CVD Coatings**: TiC, TiCN for specific applications - **Nitriding**: For improved surface hardness and wear resistance - **Oxide Coatings**: For improved lubrication in certain applications #### **Benefits of Coatings** - **Extended Tool Life**: 100-300% improvement with PVD coatings - **Increased Cutting Speeds**: 20-40% higher speeds possible with coatings - **Improved Surface Finish**: Better chip flow and reduced built-up edge - **Reduced Friction**: Lower cutting forces and temperatures - **Enhanced Thermal Barrier**: Protection against heat penetration --- ### **Comparison with Other High Speed Steels** | Property | Speed Star (M2) | M1 | M7 | M35 (5% Co) | M42 (8% Co) | |----------|-----------------|----|----|-------------|-------------| | **Red-Hardness** | Very Good | Good | Very Good | Excellent | Excellent | | **Wear Resistance** | Good | Fair | Very Good | Very Good | Excellent | | **Toughness** | Good | Very Good | Good | Good | Fair | | **Maximum Hardness (HRC)** | 65-67 | 64-66 | 65-67 | 65-67 | 67-70 | | **Grindability** | Good | Very Good | Fair | Fair | Poor | | **Cost Factor** | Low | Low | Medium | Medium | High | | **Primary Application** | General HSS tools | Low-cost HSS | High-wear HSS | General with better red-hard | Premium HSS | --- ### **Design and Manufacturing Considerations** #### **Optimal Design Practices** - **Generous Radii**: Minimum 0.5mm (0.020") on cutting edges - **Proper Clearances**: Adequate relief angles for chip clearance - **Balanced Designs**: For rotating tools to minimize vibration - **Adequate Core Strength**: For tools subject to torsional loads - **Coolant Channels**: Proper design for effective cooling #### **Heat Treatment Best Practices** 1. **Proper Preheating**: Essential to prevent thermal shock 2. **Precise Austenitizing**: Critical temperature control for optimal properties 3. **Adequate Quenching**: Proper medium and agitation 4. **Multiple Tempers**: Essential for maximum hardness and stability 5. **Atmosphere Control**: Protection against decarburization and oxidation #### **Common Pitfalls to Avoid** - Insufficient preheating (causes cracking) - Overheating during austenitizing (causes grain growth and retained austenite) - Inadequate tempering (insufficient secondary hardening) - Grinding burns (causes thermal cracking) - Improper storage leading to corrosion --- ### **Economic Justification** #### **Cost-Benefit Analysis** - **Extended Tool Life**: Longer service life than carbon or low-alloy tool steels - **Higher Productivity**: Ability to use higher cutting speeds and feeds - **Versatile Application**: One tool material for multiple operations - **Reduced Downtime**: Fewer tool changes and regrinding operations - **Improved Part Quality**: Better surface finishes and dimensional accuracy **Typical ROI**: 2-6 months in general machining operations #### **Total Cost Factors** 1. **Material Cost**: Moderate for HSS category 2. **Manufacturing Cost**: Higher due to difficult machining 3. **Heat Treatment Cost**: Complex and energy-intensive 4. **Tool Performance**: Excellent for general metal cutting 5. **Maintenance**: Regular regrinding required --- ### **Industry-Specific Applications** #### **General Machining** - **Job Shops**: Versatile tools for varied work - **Maintenance Shops**: General-purpose cutting tools - **Tool and Die Shops**: For mold and die machining #### **Automotive Manufacturing** - **Engine Component Machining**: Drilling, tapping, and milling operations - **Transmission Parts**: Gear cutting and finishing - **Chassis Components**: Drilling and reaming operations #### **Aerospace Industry** - **Component Machining**: For aluminum, titanium, and steel parts - **Tooling**: For composite material machining - **Maintenance and Repair**: For aircraft component servicing #### **Mold and Die Industry** - **Mold Machining**: For plastic injection and die casting molds - **EDM Electrodes**: For electrical discharge machining - **Finishing Tools**: For mold polishing and texturing --- ### **Technical Specifications & Quality Assurance** #### **Quality Standards** - **Micro-Cleanliness**: Meets ASTM E45 requirements - **Carbide Distribution**: Uniform carbide structure - **Decarburization**: Controlled to specified limits - **Hardness Uniformity**: Consistent through specified sections - **Dimensional Tolerances**: Available to precision standards #### **Available Forms** - **Round Bars**: 3mm to 150mm diameter - **Flat Bars**: Various thicknesses and widths - **Tool Blanks**: Pre-cut for specific tool types - **Sheets and Plates**: For larger tool components - **Wire**: For special applications - **Forgings**: Custom shapes and sizes #### **Certification** - Mill test certificates with full chemical analysis - Hardness and microstructure reports - Traceability to heat and melt numbers - Compliance with international standards --- ### **Safety and Environmental Considerations** #### **Material Safety** - Contains tungsten and other alloying elements - Grinding dust requires proper ventilation - Material safety data sheets available - Standard metalworking precautions apply #### **Regulatory Compliance** - ROHS compliant - REACH registered - Conforms to international environmental standards --- ### **Conclusion** Carpenter Speed Star® (AISI M2) represents the benchmark in general-purpose high speed steels, offering an optimal balance of red-hardness, wear resistance, toughness, and cost-effectiveness. Its position as the most widely used HSS grade worldwide is testament to its versatile performance across countless machining applications. **Key Advantages Summary:** 1. **Excellent Red-Hardness**: Maintains cutting ability at high temperatures 2. **Good Wear Resistance**: Suitable for abrasive materials 3. **Balanced Toughness**: Resists chipping and breakage 4. **Cost-Effective Performance**: Premium results at reasonable cost 5. **Proven Reliability**: Decades of proven performance in industry For manufacturers and toolmakers requiring high-performance cutting tools that can handle a wide range of materials and operations, Speed Star provides a reliable, proven solution. While requiring proper heat treatment and application, its performance advantages in general metal cutting consistently justify its specification. When the application demands a high speed steel that offers a balanced combination of properties for general machining operations, Carpenter Speed Star stands as the engineered solution backed by Carpenter's metallurgical expertise and quality assurance. Its status as an industry standard ensures widespread availability, technical support, and proven performance across global manufacturing sectors. --- *For specific application recommendations, heat treatment guidelines, or technical assistance, consult with Carpenter Technology's technical services team. Always refer to the latest technical data sheets for current specifications and processing recommendations.* -:- For detailed product information, please contact sales. -: Carpenter Speed Star® High Speed Steel (Red-Hard) (AISI M2) Specification Dimensions Size： Diameter 20-1000 mm Length <6941 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Carpenter Speed Star® High Speed Steel (Red-Hard) (AISI M2) Properties -:- For detailed product information, please contact sales. -:

Applications of Carpenter Speed Star® High Speed Steel Rod (Red-Hard) (AISI M2) -:- For detailed product information, please contact sales. -: Chemical Identifiers Carpenter Speed Star® High Speed Steel Rod (Red-Hard) (AISI M2) -:- For detailed product information, please contact sales. -:

Packing of Carpenter Speed Star® High Speed Steel Rod (Red-Hard) (AISI M2) -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Rod drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3412 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition