AISI Type M35 Molybdenum High Speed Tool Steel Rod/Bar (UNS T11335)

AISI Type M35 Molybdenum High Speed Tool Steel Rod (UNS T11335) Product Information -:- For detailed product information, please contact sales. -: AISI Type M35 Molybdenum High Speed Tool Steel Rod (UNS T11335) Synonyms -:- For detailed product information, please contact sales. -:

AISI Type M35 Molybdenum High Speed Tool Steel (UNS T11335) Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI Type M35 (M2+5%Co) Cobalt-Enhanced High-Speed Tool Steel (UNS T11335)** ## **Overview** AISI Type M35, commonly known as **"M2+5%Co"**, is a **cobalt-enhanced molybdenum-tungsten high-speed steel** that represents the **most widely used cobalt-bearing HSS grade globally**. By adding **4.50-5.50% cobalt** to the proven M2 composition, M35 delivers significantly **improved hot hardness, red hardness, and cutting performance at elevated temperatures** while maintaining the excellent all-around characteristics of M2. This grade has become the **industry standard for demanding cutting applications** where standard M2 reaches its temperature limits. **Key Advantages:** - **Significantly Improved Hot Hardness:** Maintains cutting edge at temperatures up to 600°C (1110°F) - **Enhanced Red Hardness:** Superior high-temperature hardness retention vs. standard M2 - **Excellent Balance of Properties:** Maintains good toughness and wear resistance - **Good Grindability:** Reasonably grindable with standard abrasives - **Proven Reliability:** Extensive industry experience and application knowledge - **Wide Availability:** Readily available from major producers worldwide **Primary Considerations:** - **Higher Cost:** 30-50% more expensive than standard M2 - **Reduced Toughness:** Slightly lower impact resistance than non-cobalt grades - **Heat Treatment Sensitivity:** Requires precise temperature control - **Not for Extreme Conditions:** Limited vs. higher-cobalt or powder metallurgy grades ## **International Designations & Standards** | Standard System | Designation | Note | |----------------|-------------|------| | **AISI/SAE (USA)** | M35 | Primary specification | | **UNS (USA)** | T11335 | Unified numbering system | | **ASTM (USA)** | A600 | High-Speed Tool Steel Standard | | **ISO (International)** | **HS6-5-2-5** | International standard (6%W-5%Mo-2%V-5%Co) | | **DIN (Germany)** | 1.3243 | Standard M35 equivalent | | **JIS (Japan)** | SKH55 | Japanese standard M35 | | **BS (UK)** | **BM35** | British standard M35 | | **GB (China)** | W6Mo5Cr4V2Co5 | Chinese standard M35 | | **AFNOR (France)** | Z85WDCV06-05-04-02-05 | French designation with cobalt | *Note: M35 is universally recognized and standardized as the premier general-purpose cobalt HSS grade, often referred to as the "workhorse" of cobalt high-speed steels.* --- ## **1. Chemical Composition (Typical, Weight %)** M35's composition is essentially M2 with strategic cobalt addition for enhanced high-temperature performance. | Element | Content (%) | Role & Metallurgical Effect | |---------|-------------|-----------------------------| | **Carbon (C)** | 0.82 - 0.92 | Slightly higher than M2 to balance cobalt's effect. Provides matrix hardness and supports carbide formation. | | **Cobalt (Co)** | 4.50 - 5.50 | **Key performance enhancer.** Increases red hardness by ~15%, improves thermal conductivity by ~20%, promotes secondary hardening, reduces retained austenite. | | **Tungsten (W)** | 5.50 - 6.75 | Same as M2. Provides hot hardness through tungsten carbide formation and solid solution strengthening. | | **Molybdenum (Mo)** | 4.50 - 5.50 | Same as M2. Works synergistically with tungsten for hot hardness and hardenability. | | **Chromium (Cr)** | 3.75 - 4.50 | Standard HSS level for hardenability, oxidation resistance, and carbide formation. | | **Vanadium (V)** | 1.75 - 2.20 | Same as M2. Forms hard vanadium carbides (VC) for wear resistance and grain refinement. | | **Silicon (Si)** | 0.20 - 0.45 | Deoxidizer and matrix strengthener. | | **Manganese (Mn)** | 0.15 - 0.40 | Enhances hardenability and aids in deoxidation. | | **Sulfur (S)** | ≤0.030 | Residual impurity. | | **Phosphorus (P)** | ≤0.030 | Residual impurity. | | **Iron (Fe)** | Balance | Matrix element. | **Metallurgical Characteristics:** - **Carbide Volume:** ~12-16% (similar to M2) - **Cobalt Distribution:** In solid solution, enhances matrix strength at high temperatures - **Secondary Hardening:** Enhanced response due to cobalt - **Retained Austenite:** Typically <5% after proper triple tempering --- ## **2. Physical & Mechanical Properties** ### **Physical Properties** | Property | Typical Value | Conditions/Notes | |----------|---------------|------------------| | **Density** | 8.18 - 8.22 g/cm³ | At 20°C (68°F) | | **Melting Range** | 1370 - 1420°C (2500 - 2590°F) | Similar to M2 | | **Thermal Conductivity** | 26 - 31 W/m·K | At 20°C (68°F) - 15-25% higher than M2 | | **Specific Heat Capacity** | 415 - 455 J/kg·K | At 20°C (68°F) | | **Coefficient of Thermal Expansion** | 10.8 - 11.5 × 10⁻⁶/K | 20-600°C (68-1110°F) range | | **Electrical Resistivity** | 0.48 - 0.56 μΩ·m | At 20°C (68°F) | | **Elastic Modulus** | 205 - 215 GPa (29.7 - 31.2 × 10⁶ psi) | At room temperature | | **Thermal Diffusivity** | 7.0 - 8.0 mm²/s | At 20°C (68°F) - Improved heat dissipation | ### **Mechanical Properties (Properly Heat-Treated)** | Property | Value Range | Heat Treatment Condition | |----------|-------------|--------------------------| | **Hardness (Annealed)** | 223 - 269 HB | Annealed condition | | **Hardness (Hardened)** | 65 - 67 HRC | Triple tempered (standard practice) | | **Hot Hardness (600°C)** | 57 - 60 HRC | After 4 hours at temperature | | **Transverse Rupture Strength** | 3400 - 4000 MPa (493 - 580 ksi) | At 66 HRC | | **Compressive Strength** | 3900 - 4500 MPa (566 - 653 ksi) | At 66 HRC | | **Impact Toughness (Charpy)** | 16 - 24 J (11.8 - 17.7 ft·lb) | At 66 HRC | | **Young's Modulus** | 205 - 215 GPa (29.7 - 31.2 × 10⁶ psi) | At room temperature | | **Fatigue Strength** | 800 - 950 MPa (116 - 138 ksi) | Rotating bending, 10⁷ cycles | ### **High-Temperature Performance Comparison** | Temperature | M35 Hardness (HRC) | M2 Hardness (HRC) | Performance Advantage | |-------------|---------------------|--------------------|-----------------------| | **20°C (68°F)** | 65-66.5 | 64-65 | +1.0-1.5 HRC | | **300°C (570°F)** | 62-64 | 60-62 | +2.0-2.5 HRC | | **450°C (840°F)** | 58-61 | 56-58 | +2.0-3.0 HRC | | **550°C (1020°F)** | 54-57 | 52-54 | +2.0-3.0 HRC | | **600°C (1110°F)** | 50-53 | 48-50 | +2.0-3.0 HRC | ### **Performance Metrics** - **Red Hardness Improvement:** 15-25% over M2 at 600°C - **Thermal Conductivity Increase:** 15-25% over M2 - **Cutting Speed Potential:** 20-40% higher than M2 for equivalent tool life - **Tool Life Expectancy:** 1.5-3.0x M2 in appropriate applications ### **Grindability Characteristics** - **Relative Grindability:** 80-90% (compared to M2 = 100%) - **Wheel Selection:** Aluminum oxide A46-J8-V standard - **Wheel Life:** 10-20% reduction vs. M2 - **Power Requirement:** 10-15% higher than M2 - **Surface Finish:** Excellent with proper technique --- ## **3. Product Applications** ### **Primary Application Areas** **1. Demanding Cutting Applications (60% of usage):** - Drills for stainless steels, heat-resistant alloys, titanium - End mills for high-temperature operations - Taps for difficult materials (stainless, high-temp alloys) - Reamers requiring precision at elevated temperatures **2. Production Tools (25% of usage):** - Gear hobs and shaper cutters for automotive/aerospace - Broaches for production machining - Milling cutters for continuous high-performance operations - Form tools requiring consistent high-temperature performance **3. Specialized Applications (15% of usage):** - Cutting tools for hardened steels (up to 50 HRC) - Tools for abrasive materials with temperature concerns - High-speed machining of alloy steels - Production tools requiring extended life between regrinds ### **Industry Application Distribution** | Industry | Market Share | Typical Applications | |----------|--------------|---------------------| | **Aerospace** | 30% | Drills, end mills for titanium/nickel alloys | | **Automotive** | 25% | Gear cutters, form tools, broaches | | **General Machining** | 20% | Drills, taps, end mills for difficult materials | | **Energy** | 15% | Valve machining, turbine components | | **Tool & Die** | 10% | Hard milling cutters, specialized tools | ### **Recommended Cutting Parameters** | Work Material | Cutting Speed (m/min) | Feed (mm/tooth) | vs M2 Improvement | Application Notes | |---------------|----------------------|-----------------|-------------------|------------------| | **Stainless Steel 304/316** | 35-55 | 0.10-0.25 | +20-35% | Use high-pressure coolant | | **Titanium Alloys** | 30-50 | 0.08-0.20 | +25-40% | Copious coolant essential | | **Inconel 718** | 20-40 | 0.05-0.15 | +30-50% | High-pressure through-tool coolant | | **Tool Steel (30-40HRC)** | 40-65 | 0.15-0.30 | +15-25% | Standard coolant adequate | | **Cast Iron** | 50-80 | 0.20-0.45 | +10-20% | Dry or minimal coolant | --- ## **4. Heat Treatment Guidelines** ### **Annealing** - **Temperature:** 850-880°C (1560-1615°F) - **Soaking Time:** 2-4 hours - **Cooling Rate:** ≤15°C/hr to 540°C, then air cool - **Resulting Hardness:** 223-269 HB - **Protection:** Salt bath or protective atmosphere recommended ### **Stress Relieving** - **After Rough Machining:** 600-650°C (1110-1200°F), 2 hours - **After Rough Grinding:** 550-600°C (1020-1110°F), 1 hour - **Cooling:** Slow furnace cool ### **Hardening (Critical Process)** 1. **Preheating (Essential):** - **First Stage:** 450-550°C (840-1020°F) - **Second Stage:** 800-850°C (1470-1560°F) - **Third Stage:** 1050-1100°C (1920-2010°F) - Optional for complex tools 2. **Austenitizing:** - **Temperature:** 1190-1220°C (2175-2230°F) - **Soaking Time:** 2-4 minutes per 25mm thickness - **Atmosphere:** **Vacuum or salt bath strongly recommended** - **Protection:** Pack methods if atmosphere control unavailable 3. **Quenching:** - **Oil Quench:** Fast oil, 40-60°C, vigorous agitation - **Salt Bath Marquench:** 500-550°C, equalize, then air cool (best for complex shapes) - **Press Quenching:** For flat tools to minimize distortion ### **Tempering (Triple Temper Minimum)** - **First Temper:** Begin at 60-80°C (140-175°F) after quenching - **Temperature:** 540-570°C (1000-1060°F) - **Cycles:** **Minimum 3 tempers, 4 recommended for critical tools** - **Duration:** 1-2 hours per temper - **Cooling:** Air cool completely between tempers - **Final Hardness:** 65-67 HRC - **Retained Austenite:** <5% after proper treatment ### **Sub-Zero Treatment (Highly Recommended)** - **Temperature:** -70 to -100°C (-95 to -150°F) - **Duration:** 2-4 hours - **Timing:** After quenching, before first temper - **Benefits:** Maximum hardness (0.5-1.5 HRC increase), dimensional stability --- ## **5. Manufacturing & Processing** ### **Machinability (Annealed)** - **Relative Machinability:** 40-50% (1% carbon steel = 100%) - **Tool Requirements:** Carbide tools essential - **Parameters:** - Turning: 20-35 m/min (65-115 SFM) with carbide - Milling: 15-25 m/min (50-80 SFM) with carbide - Drilling: 8-12 m/min (25-40 SFM) with carbide - **Coolant:** Heavy-duty soluble oil or synthetic ### **Grinding Operations** - **Wheel Selection:** Aluminum oxide A46-J8-V or premium grades - **Parameters:** - Wheel Speed: 25-30 m/s (5000-6000 SFPM) - Infeed: 0.005-0.015 mm/pass - Crossfeed: 1-3 mm/pass - Spark-out: 2-3 passes recommended - **Coolant:** High-volume water-based synthetic - **Dressing:** Frequent dressing for optimal results ### **Quality Grades Available** | Grade Type | Description | Applications | |------------|-------------|--------------| | **Standard M35** | Conventional melting | General purpose cobalt tools | | **Premium M35** | Special processing | Critical aerospace/automotive | | **PM M35** | Powder metallurgy | Superior grindability, toughness | | **Surface Enhanced** | Special treatments | Maximum performance tools | --- ## **6. Comparative Analysis** ### **vs. Other Cobalt HSS Grades** | Property | M35 | M2 | M42 | T15 | |----------|-----|----|-----|-----| | **Cobalt Content** | 4.50-5.50% | 0% | 7.50-8.50% | 4.75-5.25% | | **Hot Hardness** | Very Good | Good | Excellent | Excellent | | **Room Temp Hardness** | 65-67 HRC | 64-65 HRC | 66-68 HRC | 66-68 HRC | | **Toughness** | Good | Very Good | Fair | Poor | | **Wear Resistance** | Good | Good | Good | Excellent | | **Grindability** | Good | Very Good | Poor | Very Poor | | **Cost Factor** | 1.4-1.6x | 1.0x | 2.0-2.2x | 2.5-3.0x | ### **Performance/Cost Positioning** | Application | M35 Performance | Cost Efficiency | Best For | |-------------|-----------------|-----------------|----------| | **General Cobalt Applications** | Excellent | Best | Most cobalt tool requirements | | **High-Temp Stainless Machining** | Very Good | Excellent | Production drilling/tapping | | **Aerospace Alloys** | Good | Very Good | Moderate temperature operations | | **Hard Machining** | Good | Good | Up to 50 HRC materials | | **High-Speed Machining** | Fair-Good | Good | Moderate speed elevation | ### **Market Position Analysis** - **Market Share:** ~40% of cobalt HSS market - **Growth Trend:** Stable, with some migration to PM grades - **Primary Competition:** PM HSS grades, coated carbide - **Future Outlook:** Continued strong position in specific applications --- ## **7. Surface Treatments & Coatings** ### **Recommended Coatings** 1. **TiAlN (Aluminum Titanium Nitride):** - Maximum temperature: 800°C - Color: Violet/black - Best for: High-temperature alloys, dry machining 2. **AlTiN (with higher Al content):** - Better oxidation resistance than TiAlN - Excellent for: Stainless steels, interrupted cuts 3. **TiCN (Titanium Carbo-Nitride):** - Higher hardness than TiN - Good for: Abrasive materials, general purpose ### **Coating Performance Data** - **Tool Life Improvement:** 2-5x uncoated life - **Cutting Speed Increase:** 20-50% possible - **Surface Finish Improvement:** 1-2 roughness grades - **Reliability:** More consistent performance ### **Pre-coating Requirements** - **Surface Finish:** <0.4 μm Ra optimal - **Edge Preparation:** Honed edges (0.03-0.08mm radius) - **Cleaning:** Ultrasonic cleaning essential - **Stress State:** Compressive surface stress preferred --- ## **8. Technical Recommendations** ### **Selection Guidelines** **Choose M35 when:** - Standard M2 lacks sufficient hot hardness - Operating temperatures regularly exceed 400°C - Production volumes justify material cost premium - Good balance of properties needed - Extensive industry experience available **Consider alternatives when:** - Maximum high-temperature performance required (M42/M15) - Extreme abrasion resistance needed (high-vanadium grades) - Severe impact conditions exist (tougher grades) - Minimum cost is critical (M2) - Powder metallurgy benefits needed (PM HSS) ### **Application Engineering** 1. **Parameter Optimization:** - Start at M2 parameters, increase speed 20-30% - Monitor tool temperature and wear - Optimize coolant delivery and type 2. **Tool Design Considerations:** - Adequate core strength for cobalt's reduced toughness - Optimized flute design for chip evacuation - Proper edge preparation and honing 3. **Process Integration:** - Machine rigidity assessment - Workholding optimization - Coolant system evaluation ### **Economic Considerations** - **Break-Even Analysis:** Calculate based on tool life improvement - **Total Cost of Ownership:** Include regrinding, downtime, quality - **ROI Period:** Typically 3-12 months in production - **Inventory Strategy:** Balance availability vs. carrying cost ### **Common Issues & Solutions** | Problem | Root Causes | Preventive Actions | |---------|-------------|-------------------| | **Premature Flank Wear** | Insufficient hardness, coating | Verify heat treatment, apply appropriate coating | | **Edge Chipping** | Excessive feed, poor edge prep | Reduce feed, improve edge honing (0.05mm radius) | | **Thermal Cracking** | Heat concentration, poor cooling | Improve coolant delivery, reduce speed | | **Catastrophic Failure** | Overload, vibration, deflection | Improve rigidity, reduce cutting forces | | **Inconsistent Performance** | Heat treatment variations | Implement strict process control | --- ## **Disclaimer** This technical datasheet provides comprehensive information about AISI Type M35 high-speed tool steel based on industry standards, technical literature, and extensive application experience. Actual performance may vary depending on: **Critical Performance Factors:** 1. **Material Quality:** Manufacturer's processes and quality control 2. **Heat Treatment:** Precision of temperature control and quenching 3. **Tool Design:** Geometry, edge preparation, structural integrity 4. **Application Conditions:** Workpiece material, machine condition, coolant effectiveness 5. **Operating Parameters:** Optimization for specific conditions **Important Usage Guidelines:** - M35 represents an optimized balance of performance and cost for demanding applications - Proper application engineering is essential for success - Performance should be validated under actual production conditions - Regular maintenance and monitoring maximize tool life and performance **Reference Standards:** - ASTM A600: Standard Specification for Tool Steel High Speed - ISO 4957: Tool steels - AMS 6390: Aerospace material specification - Manufacturer's technical data and processing guidelines This information represents current industry knowledge and best practices. Technology and standards evolve continuously, so users should: - Verify specifications with materials suppliers - Conduct application-specific testing for critical applications - Consult with technical specialists for unique requirements - Stay informed about developments in tool materials and coatings Always prioritize safety in all aspects of tool handling, operation, and maintenance, adhering to all applicable industry standards and regulations. -:- For detailed product information, please contact sales. -: AISI Type M35 Molybdenum High Speed Tool Steel (UNS T11335) Specification Dimensions Size： Diameter 20-1000 mm Length <6722 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. -: AISI Type M35 Molybdenum High Speed Tool Steel (UNS T11335) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI Type M35 Molybdenum High Speed Tool Steel Rod (UNS T11335) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI Type M35 Molybdenum High Speed Tool Steel Rod (UNS T11335) -:- For detailed product information, please contact sales. -:

Packing of AISI Type M35 Molybdenum High Speed Tool Steel Rod (UNS T11335) -:- 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 3193 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