Bohler-Uddeholm,BÖHLER M268 VMR® Plastic Mold Steel Flange

1,We Manufacturing processes are primarily classified into four types: 1:Forging, 2:Casting, 3:Cutting, 4:Rolling. 2,We can manufacture in accordance with these standards. Standards: GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards). Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others. The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500. Flange Classification 1. **According to Chemical Industry Standards:** Flanges are classified as follows: Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)). 2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows: Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation). 3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows: Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange. 4. **According to Connection Method/Type:** Flanges are classified as follows: Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc. 5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges. 6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges. A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts." -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Flange Product Information -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Flange Synonyms -:- For detailed product information, please contact sales. -:

Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Product Information -:- For detailed product information, please contact sales. -: # **Böhler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel** ## **Product Overview** **BÖHLER M268 VMR®** is a premium **chromium-nickel-molybdenum alloyed plastic mold steel** manufactured using Böhler-Uddeholm's proprietary **VMR® (Vacuum Melted and Remelted)** technology. This advanced dual vacuum melting process ensures **exceptional internal cleanliness, superior microstructural homogeneity, and minimal anisotropy**. Designed as a high-performance, through-hardening mold steel, M268 VMR® delivers an **excellent balance of toughness, wear resistance, polishability, and dimensional stability**, making it ideally suited for demanding plastic injection molds requiring high precision, complex geometries, and superior surface finishes. --- ## **1. Key Characteristics & Advantages** * **Exceptional Toughness:** Offers high impact strength and resistance to cracking, particularly valuable for molds with thin ribs, delicate cores, and high-aspect-ratio features prone to mechanical stress. * **Superior Internal Cleanliness:** The VMR® process (Vacuum Induction Melting + Vacuum Arc Remelting) drastically reduces non-metallic inclusions and gases (O, H, N), resulting in flawless polishability and enhanced fatigue resistance. * **Excellent Polishability:** Capable of achieving high-grade mirror finishes (up to SPI A-2 / B-1) due to its homogeneous, inclusion-free microstructure. * **Good Wear Resistance:** Provides adequate resistance to abrasion from standard and moderately filled engineering plastics. * **High Dimensional Stability:** Exhibits predictable and minimal distortion during heat treatment, crucial for maintaining tight tolerances in precision molds. * **Good Machinability:** In the annealed state, offers favorable machining characteristics for efficient mold manufacturing. * **Good Nitriding Response:** Readily accepts nitriding surface treatments to significantly enhance surface hardness and wear resistance without compromising core toughness. * **Isotropic Properties:** The VMR® process ensures uniform mechanical behavior in all directions (longitudinal and transverse). --- ## **2. Typical Chemical Composition (Weight %)** | Element | Carbon (C) | Chromium (Cr) | Nickel (Ni) | Molybdenum (Mo) | Manganese (Mn) | Silicon (Si) | | :--- | :---: | :---: | :---: | :---: | :---: | :---: | | **Content** | **0.15 - 0.20** | **1.40 - 1.70** | **3.80 - 4.30** | **0.15 - 0.25** | **1.30 - 1.60** | **0.15 - 0.35** | **Alloying Rationale:** * **Nickel (4.0%):** The key alloying element. Significantly increases toughness and hardenability, promotes a fine-grained microstructure, and improves impact strength at low temperatures. * **Chromium (1.55%) & Molybdenum (0.2%):** Provide hardenability and contribute to strength. Molybdenum also enhances toughness and refines the grain structure. * **Low Carbon (0.18%):** Optimized to prioritize toughness and weldability while providing sufficient hardness after heat treatment. This minimizes the risk of stress cracking in complex molds. * **Manganese (1.45%):** Enhances hardenability and works as a deoxidizer. * **VMR® Process Impact:** This dual vacuum melting is critical. It removes impurities and gases that could act as initiation sites for polish lines, pits, or cracks, guaranteeing the steel's performance in high-quality surface applications. --- ## **3. Physical & Mechanical Properties** ### **Physical Properties:** * **Density:** ~7.85 g/cm³ * **Thermal Conductivity:** ~36 W/(m·K) at 20°C * **Modulus of Elasticity:** ~205 GPa * **Coefficient of Thermal Expansion:** ~12.5 x 10⁻⁶/K (20-100°C) ### **Heat Treatment & Mechanical Data:** * **Annealed Hardness:** ~210 HBW * **Austenitizing Temperature:** 840 - 870°C (1545 - 1600°F) * **Quenching Medium:** Oil or air. For optimal properties and minimal distortion, oil quenching is often preferred. * **Tempering Temperature Range:** 300 - 550°C (570 - 1020°F). **Double tempering is recommended.** * **Typical Working Hardness:** **38 - 44 HRC** * A common specification is **40-42 HRC** (tempered at ~400-450°C), providing an optimal balance of toughness, strength, and polishability for most demanding mold applications. * **Impact Toughness (Charpy V):** Exceptionally high, typically >50 J at 40 HRC. * **Core Strength:** High yield strength supports the hard nitrided surface in treated applications. --- ## **4. Primary Applications** M268 VMR® is engineered for high-performance, precision plastic injection molds where reliability, surface finish, and toughness are critical. * **Large, Complex Injection Molds:** Automotive components (bumpers, dashboards, door panels), appliance housings, and technical parts requiring high dimensional stability. * **Molds with Delicate Features:** Thin-walled components, high-aspect-ratio ribs, and intricate cores where resistance to bending and breakage is paramount. * **High-Gloss Surface Molds:** Consumer electronics, automotive interior trim, and appliance parts requiring very good surface finishes. * **Engineering Plastic Molds:** For polymers like PA (Nylon), PBT, PC, POM, and PPS, where good wear resistance and toughness are needed. * **Mold Bases and Support Plates:** For large mold systems where high strength and toughness of the backing structure are essential. * **General Precision Tooling:** Components requiring a combination of good machinability, toughness, and consistent heat treatment response. --- ## **5. Relevant International Standards & Comparable Grades** M268 VMR® is a proprietary Böhler-Uddeholm grade. Its chemistry places it in the family of nickel-alloyed mold steels, with the VMR® quality being a key differentiator. | Standard | Grade / Designation | Country/Region | Similarity / Key Difference | | :--- | :--- | :--- | :--- | | **Proprietary (Böhler-Uddeholm)** | **M268 VMR®** | International | The reference premium Ni-alloyed mold steel with VMR® quality. | | **AISI / ASTM** | **P20+Ni Modified / 6F7** | USA | Similar nickel-containing mold steel classification. M268 defines a specific, high-quality composition. | | **DIN / Werkstoff** | **1.2738 (≈35CrNiMo6)** | Germany/EU | The common pre-hardened mold steel with nickel. M268 VMR® is supplied annealed, allowing for custom through-hardening, and offers superior cleanliness. | | **JIS** | **SNCM8 / equivalent** | Japan | Japanese Ni-Cr-Mo alloy steel. M268 is optimized specifically for mold performance. | | **Other Premium Grades** | **IMPAX® SUPREME (Hardened)** | Uddeholm | A pre-hardened Ni-alloyed steel. M268 VMR® offers the flexibility of custom through-hardening from an annealed state with guaranteed VMR® cleanliness. | | **Quality Benchmark** | **VMR®** | N/A | This designation, not a chemistry, is crucial. It guarantees a level of internal purity and homogeneity beyond standard air-melted or single vacuum-melted steels. | **Important:** Specifying **"M268 VMR®"** ensures receipt of material with the guaranteed internal cleanliness and consistency required for high-performance, high-finish molds. --- ## **6. Processing & Fabrication Guidelines** * **Machining:** **Excellent machinability** in the soft-annealed condition. Use sharp carbide tools. The VMR® structure provides predictable tool wear and good surface finish from machining. * **Heat Treatment:** For optimal properties, through-harden after machining. 1. Austenitize in a controlled atmosphere or vacuum furnace to prevent decarburization. 2. Quench in well-agitated oil. 3. **Temper immediately and double temper** for best toughness and dimensional stability. * **Stress Relieving:** A stress relief at 600-650°C after rough machining is highly recommended for complex molds. * **Grinding & Polishing:** Grinds and polishes well. The clean VMR® structure allows for high-quality surface finishes without "pulling out" inclusions. * **Welding:** **Good weldability** due to low carbon content. Use appropriate pre-heat (200-300°C) and post-weld heat treatment (tempering) for critical areas. Use a soft, crack-resistant filler metal. * **Surface Treatment (Highly Recommended):** * **Nitriding (Gas or Plasma):** The most common enhancement. Produces a hard, wear-resistant surface layer (up to 700-900 HV) with excellent anti-sticking properties, while the tough M268 core provides support. Ideal for gates, runners, and ejector areas. * **EDM:** Suitable. A low-temperature stress relief after EDM is advisable. --- ## **7. Conclusion** **BÖHLER M268 VMR®** is a **high-reliability, high-performance mold steel** that expertly balances the often-conflicting demands of **toughness, polishability, and manufacturability**. Its nickel-alloyed chemistry provides the backbone for exceptional impact resistance, making it a safe choice for complex, fragile mold designs. The **VMR® manufacturing process** elevates it from a standard material to a premium one, ensuring that the inherent benefits of the alloy design are fully realized through exceptional internal purity. This directly translates to better polishability, more predictable heat treatment, and reduced risk of defects in the final mold. For mold makers designing tools for large, complex parts, engineering plastics, or applications where mold breakage is a significant concern, M268 VMR® offers a robust and proven solution. It provides the safety margin of high toughness without sacrificing the ability to achieve excellent surface finishes or to be easily enhanced with nitriding for demanding production runs. -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6909 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. -: Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Flange -:- For detailed product information, please contact sales. -: Chemical Identifiers Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Flange -:- For detailed product information, please contact sales. -:

Packing of Bohler-Uddeholm BÖHLER M268 VMR® Plastic Mold Steel Flange -:- 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 Flange 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 3380 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