Latrobe LSS™ D5 Tool Steel (ASTM D5)

Latrobe LSS™ D5 Tool Steel (ASTM D5) Product Information -:- For detailed product information, please contact sales. -: Latrobe LSS™ D5 Tool Steel (ASTM D5) Synonyms -:- For detailed product information, please contact sales. -:

Latrobe LSS™ D5 Tool Steel (ASTM D5) Product Information -:- For detailed product information, please contact sales. -: # **Latrobe LSS™ D5 Tool Steel (ASTM D5)** ## **Product Overview** Latrobe LSS™ D5 is a specialized, high-carbon, high-chromium **air-hardening** cold work tool steel that conforms to the ASTM D5 specification. Distinguished by its significant **cobalt addition**, D5 is engineered to deliver **superior performance at elevated temperatures**, offering enhanced **red-hardness (hot hardness) and resistance to tempering-back** compared to standard D-series steels like D2 and D3. This makes it the ideal choice for applications involving frictional heat generation, such as certain cold forming operations, or for tooling that benefits from higher tempering temperatures to achieve greater toughness without excessive loss of hardness. ## **Key Features & Benefits** * **Enhanced Hot Hardness & Temper Resistance:** The 2.5-3.5% cobalt content significantly improves the steel's ability to retain hardness at elevated temperatures (up to ~425°C / 800°F), preventing softening during high-speed or high-pressure operations that generate heat. * **Exceptional Abrasive Wear Resistance:** Inherits the high volume of hard chromium carbides characteristic of D-series steels, providing outstanding resistance to abrasive wear in demanding service. * **Good Dimensional Stability:** As an air-hardening grade, it offers minimal and predictable dimensional change during heat treatment, superior to oil-hardening grades like D3, making it suitable for more complex geometries. * **Deep Hardenability:** Can be through-hardened in substantial cross-sections via air quenching, ensuring uniform properties throughout the tool. * **Optimized Toughness at High Hardness:** Can be tempered at higher temperatures to achieve a favorable balance of toughness and wear resistance, often maintaining a hardness level (e.g., 58-60 HRC) that would require lower, less toughening tempering temperatures in standard D2. ## **International Standard & Designations** * **Primary Standard:** **ASTM A681-08 (R2019):** Standard Specification for Tool Steel Alloy. * **Grade:** **D5** * **Manufacturer's Designation:** **Latrobe LSS™ D5** * **Unified Numbering System (UNS):** **T30405** * **Common International Equivalents:** * **ISO:** No direct, universally adopted equivalent. Functionally similar to modified high-Cr steels with Co. * **Germany (DIN/W-Nr.):** The closest conceptual equivalent is a cobalt-modified version of **1.2379**, such as **~1.2399**. * **Japan (JIS):** No direct JIS equivalent. ## **Chemical Composition (%, typical - ASTM D5)** The key differentiator is the deliberate addition of cobalt. | Carbon (C) | Chromium (Cr) | Cobalt (Co) | Molybdenum (Mo) | Vanadium (V) | Manganese (Mn) | Silicon (Si) | Iron (Fe) | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | 1.40 - 1.60 | 11.00 - 13.00 | 2.50 - 3.50 | 0.70 - 1.20 | 0.70 - 1.20 | 0.20 - 0.60 | 0.10 - 0.60 | Balance | ## **Physical & Mechanical Properties (Typical)** | Property | Value / Description | | :--- | :--- | | **Density** | ~7.7 g/cm³ (0.278 lb/in³) | | **Hardness (Annealed)** | 215-250 HB (Brinell) | | **Hardness (Heat Treated)** | **58 - 62 HRC** (Standard working range)
**Can be tempered at 500-540°C (930-1000°F)** and still retain 58-60 HRC, demonstrating its superior temper resistance. | | **Austenitizing Temperature** | 995 - 1040°C (1825 - 1900°F) | | **Quenching Medium** | Air (Still or Forced) | | **Tempering Temperature** | 180 - 540°C (355 - 1000°F). **Double tempering is essential.** Can utilize higher tempering ranges (480-540°C) to achieve a unique combination of high hardness and improved toughness. | | **Dimensional Change on Hardening** | Similar to D2; low expansion. | | **Toughness** | Moderate, comparable to or slightly better than D2 when tempered at equivalent hardness levels. | | **Red Hardness** | Good. Superior to D2 and D3, suitable for applications where frictional heating is a concern. | ## **Product Applications** Latrobe LSS™ D5 is specified for demanding cold work applications where heat generation or the need for a high-temperature temper is a factor. * **Cold Forming Dies & Punches:** For forming high-strength or abrasive materials where significant frictional heat is generated. * **Thread Rolling Dies:** For rolling hard or abrasive materials, where the die temperature rises during operation. * **Extrusion Dies & Mandrels** (Cold): For metals where die heating occurs. * **Wear Parts & Rolls** operating in warm environments or under conditions that cause work-piece heating. * **Blanking & Piercing Dies** for very long production runs on abrasive materials, where its enhanced temper resistance ensures consistent performance. * **Tools requiring a high tempering temperature** for stress relief or dimensional stabilization while maintaining high hardness. ## **Processing & Heat Treatment Notes** * **Machining:** Similar to D2; good machinability in the properly annealed (spheroidized) condition. * **Heat Treatment:** Follows similar guidelines to D2 but takes advantage of its wider tempering window. **Thorough preheating** is required. Austenitize in a controlled atmosphere or vacuum furnace. Air quench. **Immediate double tempering is mandatory.** The high cobalt content allows effective use of higher second tempering temperatures (e.g., 540°C/1000°F) to maximize toughness while retaining useful hardness. * **Grinding:** Grinds similarly to D2. Use sharp wheels and ample coolant to manage heat. * **Surface Treatments:** An excellent candidate for nitriding and PVD coatings to further enhance surface performance. --- **Disclaimer** *This product description provides typical information for D5 tool steel. Latrobe LSS™ D5 is a specialized grade whose properties are highly dependent on precise heat treatment. For critical applications, always consult the latest official technical data sheets and processing guidelines from Latrobe Specialty Steel to determine suitability and optimal processing parameters.* -:- For detailed product information, please contact sales. -: Latrobe LSS™ D5 Tool Steel (ASTM D5) Specification Dimensions Size： Diameter 20-1000 mm Length <5356 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. -: Latrobe LSS™ D5 Tool Steel (ASTM D5) Properties -:- For detailed product information, please contact sales. -:

Applications of Latrobe LSS™ D5 Tool Steel (ASTM D5) -:- For detailed product information, please contact sales. -: Chemical Identifiers Latrobe LSS™ D5 Tool Steel (ASTM D5) -:- For detailed product information, please contact sales. -:

Packing of Latrobe LSS™ D5 Tool Steel (ASTM D5) -:- 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 1827 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