Alloy 39，Low Expansion 39 Alloy Bar(Round bar, Flat bar)，,E FORU

British Specs:，American Specs:，German Specs:

### **Product Introduction: Alloy 39 / Low Expansion 39 Alloy Bar (Round Bar & Flat Bar)** **Premium Bar Stock for Precision Engineering and Thermal Management Applications** **Alloy 39 Bar** is a specialized iron-nickel-cobalt alloy available in both round and flat bar configurations, engineered to provide exceptional dimensional stability and controlled thermal expansion characteristics. This advanced material offers an optimal combination of low thermal expansion properties, excellent machinability, and superior mechanical strength, making it ideal for precision instruments, optical systems, and critical aerospace components where thermal stability is paramount. --- #### **1. Chemical Composition (Weight %)** | Element | Content (%) | Control Significance | | :--- | :--- | :--- | | **Nickel (Ni)** | 38.0 - 40.0 | Primary thermal expansion control | | **Cobalt (Co)** | 14.0 - 16.0 | Secondary expansion adjustment | | **Iron (Fe)** | Balance | Matrix structure formation | | **Manganese (Mn)** | 0.50 max | Deoxidation and sulfur control | | **Silicon (Si)** | 0.30 max | Deoxidation agent | | **Carbon (C)** | 0.05 max | Weldability and formability | | **Chromium (Cr)** | 0.20 max | Surface integrity | | **Aluminum (Al)** | 0.10 max | Deoxidation element | | **Copper (Cu)** | 0.20 max | Minor alloying element | | **Titanium (Ti)** | 0.10 max | Grain refinement | | **Sulfur (S)** | 0.015 max | Hot workability control | | **Phosphorus (P)** | 0.015 max | Ductility preservation | * **Precision Engineering:** The optimized nickel-cobalt balance ensures consistent low thermal expansion characteristics, while stringent impurity control guarantees superior processing performance and long-term dimensional stability. --- #### **2. Physical Properties** | Property | Value | Test Condition | | :--- | :--- | :--- | | **Density** | 8.17 g/cm³ | 20°C | | **Melting Point** | 1450°C | Approximate | | **Thermal Conductivity** | 14.5 W/m·K | 20°C | | **Mean CTE (20-300°C)** | 4.5-5.5 × 10⁻⁶/°C | - | | **Specific Heat Capacity** | 460 J/kg·K | 20°C | | **Electrical Resistivity** | 75 μΩ·cm | 20°C | | **Curie Temperature** | 230°C | - | | **Modulus of Elasticity** | 152 GPa | 20°C | --- #### **3. Mechanical Properties** | Property | Round Bar (Annealed) | Flat Bar (Annealed) | | :--- | :--- | :--- | | **Tensile Strength** | 70-85 ksi (483-586 MPa) | 72-88 ksi (496-607 MPa) | | **Yield Strength (0.2%)** | 40-55 ksi (276-379 MPa) | 42-58 ksi (290-400 MPa) | | **Elongation** | 30-40% | 28-38% | | **Reduction of Area** | 55-65% | 50-60% | | **Hardness** | HRB 75-85 | HRB 78-88 | | **Impact Toughness** | 40-60 ft-lb | 35-55 ft-lb | --- #### **4. Product Specifications & Applications** **Round Bar Applications:** - Precision shafting for optical and measuring systems - Laser system components and mounting elements - Semiconductor equipment guide rods - Instrumentation structural members - Aerospace alignment components **Flat Bar Applications:** - Optical mounting platforms and bases - Machine tool structural elements - Electronic package substrates - Precision fixture components - Instrument frame structures **Industry Applications:** * **Precision Manufacturing:** - Coordinate measuring machine components - Optical comparator stages - Metrology equipment structures - Precision gauge fixtures * **Aerospace & Defense:** - Inertial navigation system mounts - Satellite instrument platforms - Avionics enclosure frames - Guidance system components * **Electronics & Semiconductor:** - Wafer handling system components - Vacuum chamber structural members - RF device mounting platforms - Clean room equipment frames * **Research & Development:** - Laboratory instrument structures - Optical test bench components - Cryogenic equipment mounts - Scientific research apparatus --- #### **5. International Standards & Specifications** **Global Standards Compliance:** - **ASTM F30:** Standard Specification for Iron-Nickel-Cobalt Alloys - **UNS K94670:** Unified Numbering System Designation - **AMS 7725:** Aerospace Material Specification - **MIL-DTL-23488:** Military Specification (Type IV) - **ISO 4950:** High Yield Strength Steel Plates - **DIN 17470:** German Industrial Standard - **JIS C2531:** Japanese Industrial Standard **Product Specifications:** **Round Bar:** - **Diameter Range:** 0.125" to 8.000" (3.175 mm to 203.2 mm) - **Diameter Tolerance:** ±0.001" to ±0.010" - **Straightness:** 0.010" per foot maximum - **Surface Finish:** 32 μin RMS or better **Flat Bar:** - **Thickness Range:** 0.125" to 3.000" (3.175 mm to 76.2 mm) - **Width Range:** 0.500" to 12.000" (12.7 mm to 304.8 mm) - **Flatness:** 0.005" per inch maximum - **Surface Condition:** Cold drawn or hot rolled --- #### **6. Technical Advantages & Processing Characteristics** **Manufacturing Benefits:** - **Excellent Machinability:** Superior chip formation and surface finish - **Good Weldability:** Compatible with common welding techniques - **Thermal Stability:** Maintains dimensional integrity under temperature variations - **Corrosion Resistance:** Suitable for most industrial environments - **Consistent Performance:** Uniform properties throughout material **Processing Guidelines:** - **Machining:** Use sharp tools with positive rake angles - **Heat Treatment:** Stress relieve at 425-540°C after severe machining - **Forming:** Excellent cold working characteristics in annealed condition - **Surface Treatment:** Compatible with various plating and coating processes **Quality Assurance:** - **Chemical Analysis:** Complete material certification - **Mechanical Testing:** Verification of all specified properties - **Dimensional Inspection:** Precision measurement capabilities - **Non-Destructive Testing:** Available as required - **Traceability:** Full material history documentation --- #### **Why Choose Our Alloy 39 Bar Products?** * **Premium Quality:** Strict control of chemical composition and microstructure * **Precision Manufacturing:** Excellent dimensional accuracy and surface quality * **Technical Expertise:** Comprehensive application support and guidance * **Quality Assurance:** Full certification and traceability * **Global Compliance:** Meets international standards and specifications * **Proven Reliability:** Extensive track record in critical applications **Additional Services:** - Custom cutting to specific lengths - Precision machining capabilities - Heat treatment processing - Surface finishing services - Comprehensive certification packages **Contact our technical team** for detailed specifications, application engineering support, and material selection guidance. We provide complete solutions for your low expansion alloy requirements, ensuring optimal performance in your most demanding precision engineering applications.

Packing of Standard Packing: 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 2757 gallon liquid totes Special package is available on request.