Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1

Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 Product Information -:- For detailed product information, please contact sales. -: Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 Synonyms -:- For detailed product information, please contact sales. -:

Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: Crucible Steel REX® M3-1 (AISI M3 Class 1) High Speed Steel** Crucible Steel REX® M3-1 is a premium high-speed steel (HSS) conforming to the AISI M3 Class 1 specification. It represents a significant evolution from the standard M2 grade, engineered to deliver **substantially enhanced wear resistance and hot hardness** for the most demanding machining applications. Positioned between M2 and the more specialized M4, M3-1 achieves its superior performance through a strategic increase in carbon and vanadium content, creating a higher volume of hard, wear-resistant carbides within the matrix. As a conventionally manufactured (ingot-cast and wrought) alloy, REX® M3-1 provides a reliable and cost-effective performance upgrade over M2 for applications where tool wear is the primary failure mode. It is specifically designed for machining **abrasive materials, high-strength alloys, and for operations requiring extended tool life under severe cutting conditions**. The "Class 1" designation distinguishes it from M3 Class 2, with Class 1 having a lower vanadium content, which results in better grindability and slightly higher toughness compared to its Class 2 counterpart, while still offering a major wear resistance improvement over M2. --- ## **1. Chemical Composition (Weight %)** The chemistry of M3-1 is a balanced, high-performance modification of the M2 baseline. | **Element** | **Carbon (C)** | **Tungsten (W)** | **Molybdenum (Mo)** | **Chromium (Cr)** | **Vanadium (V)** | **Cobalt (Co)** | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **Content** | **1.00 - 1.10** | 5.75 - 6.50 | 4.75 - 5.50 | 3.75 - 4.50 | **2.30 - 2.80** | - | | **Role** | Increased level (vs. M2) enables the formation of more vanadium and molybdenum carbides, directly boosting wear resistance and attainable hardness. | Contributes to hot hardness, abrasion resistance, and secondary hardening. | Primary agent for hardenability and hot hardness; works synergistically with tungsten. | Ensures deep hardenability and provides moderate oxidation resistance. | **Key differentiator.** The elevated vanadium content (2.3-2.8%) forms a significantly higher volume of extremely hard vanadium carbides (VC) than M2, providing **superior abrasion resistance**. | Not present in standard M3-1. (Cobalt-bearing variants exist as separate grades, e.g., M35, M36). | *Note: Iron (Fe) constitutes the remainder. The composition can be viewed as a bridge between M2 and M4, with vanadium content higher than M2 but lower than M4 Class 2 (~4-4.5% V).* --- ## **2. Physical & Mechanical Properties** *Typical properties after proper heat treatment to 64-66 HRC.* * **Density:** ~8.10 g/cm³ (0.292 lb/in³) * **Modulus of Elasticity:** ~215 GPa (31.2 x 10⁶ psi) * **Thermal Conductivity:** Moderate for a HSS. * **Hot Hardness (Red Hardness):** **Very Good to Excellent.** Maintains hardness effectively at elevated temperatures (above 550°C / 1020°F), suitable for high-speed and high-feed machining. * **Hardness (Typical Working Range):** **63 - 67 HRC.** Most commonly used at **64-66 HRC**, leveraging its high carbide content for maximum wear life. * **Abrasion Resistance:** **Excellent.** Significantly better than M2, often by 30-50% or more, due to the higher vanadium carbide volume. This is the primary reason for selecting M3-1 over M2. * **Toughness:** **Good for its wear resistance level.** Offers lower toughness than M2 but higher than M3 Class 2 or M4. It provides a practical balance, being more resistant to chipping than higher-vanadium steels while still offering much better wear resistance. * **Grindability:** **Fair to Difficult.** More challenging than M2 due to the increased volume of hard vanadium carbides, but easier than M3 Class 2 or M4. Requires appropriate grinding wheels and techniques. --- ## **3. Heat Treatment** Heat treatment is critical and requires precise control to optimize the carbide solutioning and achieve the desired balance of properties. * **Annealing:** Heat to 870-900°C (1600-1650°F), slow cool. Annealed hardness: 240-280 HB. * **Stress Relieving:** 650-675°C (1200-1250°F), hold, then slow cool. * **Preheating:** **Critical.** Use a double preheat: First at 540-650°C (1000-1200°F), then at 815-870°C (1500-1600°F). * **Austenitizing:** **1190-1220°C (2175-2230°F).** A common range is **1200-1210°C (2190-2210°F)**. Higher temperatures increase wear resistance but reduce toughness. * **Quenching:** Air quench, salt bath quench, or controlled gas quench. * **Tempering:** **Mandatory Multiple Tempers.** Temper immediately after quenching. **Minimum of two tempers** (three are often recommended), each for 2 hours. **Typical tempering range: 540-570°C (1000-1060°F).** Exhibits a strong secondary hardening response. * **Sub-Zero Treatment:** Commonly recommended between quenching and tempering to transform retained austenite, ensuring maximum hardness and dimensional stability. --- ## **4. Key Applications** REX® M3-1 is the material of choice for demanding applications where M2 tools wear out too quickly. * **Machining Abrasive Materials:** Gear hobs, broaches, and milling cutters for stainless steels, high-temperature alloys, and hardened cast irons. * **High-Performance Cutting Tools:** Form tools, end mills, and drills for production environments requiring extended tool life and reduced changeover frequency. * **Cold Work Tooling for Abrasive Materials:** Punches, dies, and forming tools used on stainless steel or other work-hardening alloys. * **Woodworking Tools for Processed Materials:** Knives and cutter heads for engineered wood products (MDF, particleboard) and abrasive hardwoods. * **Precision Wear Parts:** Components requiring a combination of high hardness and good wear resistance under load. --- ## **5. International Standards & Cross-References** Crucible REX® M3-1 conforms to the AISI M3 Class 1 (sometimes written as M3-1) specification. * **AISI/SAE:** **M3 Class 1** * **UNS:** T11313 * **European (EN):** **HS 6-5-3** (This EN grade broadly covers the M3 type composition). * **Japanese (JIS):** **SKH53** (SKH53 typically represents this level of vanadium content). * **ISO:** HS6-5-3 * **Common Trade Names:** M3-1 HSS, M3 Type 1. --- ## **6. Advantages & Limitations** **Advantages:** * **Significant Wear Resistance Upgrade:** Provides a major, cost-effective step up in tool life compared to M2 for abrasive applications. * **Good Balance of Wear and Toughness:** Offers a more practical balance for general severe service than the more wear-focused but brittle M3 Class 2 or M4. * **Maintains Good Hot Hardness:** Suitable for productive machining speeds. * **Proven, Standardized Grade:** A well-understood specification with predictable performance. **Limitations:** * **Lower Toughness than M2:** More susceptible to chipping under severe interrupted cuts or poor setup conditions. * **More Difficult to Grind:** Increases sharpening time and cost compared to M2. * **Anisotropic Properties:** As a wrought steel, transverse toughness is lower than longitudinal toughness. * **Not the Ultimate in Wear Resistance:** For the most extreme abrasive conditions, M3 Class 2, M4, or PM grades are more suitable. --- ## **7. Summary** **Crucible Steel REX® M3-1 is the definitive engineering solution for when M2 high-speed steel is no longer sufficient.** It delivers a substantial and reliable increase in wear resistance and tool life for machining abrasive and tough materials, filling the critical performance gap between the ubiquitous M2 and the more specialized high-vanadium grades. For manufacturing engineers seeking to boost productivity, reduce tooling costs per part, and tackle more challenging materials without moving to exotic alloys, M3-1 provides an optimal balance of enhanced performance, manufacturability, and cost. It is the logical and powerful next step for operations that have pushed M2 to its limits. -:- For detailed product information, please contact sales. -: Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 Specification Dimensions Size： Diameter 20-1000 mm Length <6985 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. -: Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 Properties -:- For detailed product information, please contact sales. -:

Applications of Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 -:- For detailed product information, please contact sales. -: Chemical Identifiers Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 -:- For detailed product information, please contact sales. -:

Packing of Crucible Steel REX® M3-1 High Speed Steel, AISI M3-1 -:- 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 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 3456 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