Alloy 39，Low Expansion 39 Alloy Rod，,E FORU

British Specs:，American Specs:，German Specs:

### **Product Introduction: Alloy 39 / Low Expansion 39 Alloy Rod** **Precision Rod Stock for Critical Low Thermal Expansion Applications** **Alloy 39 Rod** is a premium iron-nickel-cobalt alloy rod specifically engineered for applications requiring exceptional dimensional stability and controlled thermal expansion characteristics. This precision-manufactured rod stock offers outstanding mechanical properties combined with low thermal expansion behavior, making it an ideal material for precision instruments, optical systems, and electronic components where dimensional integrity under thermal cycling is paramount. --- #### **1. Chemical Composition (Weight %)** | Element | Content (%) | Control Purpose | | :--- | :--- | :--- | | **Nickel (Ni)** | 38.0 - 40.0 | Primary expansion control | | **Cobalt (Co)** | 14.0 - 16.0 | Secondary expansion adjustment | | **Iron (Fe)** | Balance | Matrix formation | | **Manganese (Mn)** | 0.50 max | Deoxidation and sulfur control | | **Silicon (Si)** | 0.30 max | Deoxidation | | **Carbon (C)** | 0.05 max | Weldability and formability | | **Chromium (Cr)** | 0.20 max | Surface stability | | **Aluminum (Al)** | 0.10 max | Deoxidation | | **Copper (Cu)** | 0.20 max | Minor alloying element | | **Titanium (Ti)** | 0.10 max | Grain refinement | | **Sulfur (S)** | 0.015 max | Hot workability | | **Phosphorus (P)** | 0.015 max | Ductility preservation | * **Optimized Composition:** The precise balance of 38-40% nickel and 14-16% cobalt ensures consistent low thermal expansion characteristics, while stringent impurity control guarantees superior machinability and thermal stability. --- #### **2. Physical Properties** | Property | Value | 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** | 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 | Annealed Condition | Cold Drawn Condition | | :--- | :--- | :--- | | **Tensile Strength** | 70-85 ksi (483-586 MPa) | 95-120 ksi (655-827 MPa) | | **Yield Strength (0.2%)** | 40-55 ksi (276-379 MPa) | 85-110 ksi (586-758 MPa) | | **Elongation** | 30-40% | 15-25% | | **Reduction of Area** | 55-65% | 45-55% | | **Hardness** | HRB 75-85 | HRB 90-100 | | **Machinability Rating** | 40% (vs. free-cutting brass) | 35% | --- #### **4. Product Specifications & Applications** **Rod Specifications:** - **Diameter Range:** 0.125" to 6.000" (3.175 mm to 152.4 mm) - **Diameter Tolerance:** ±0.001" to ±0.005" (size dependent) - **Length:** Standard 12-foot rods, custom lengths available - **Straightness:** 0.010" per foot maximum - **Surface Finish:** 32 μin RMS or better - **Condition:** Annealed, centerless ground, or cold drawn **Primary Applications:** * **Precision Instrumentation:** - Laser system mounting rods - Optical bench components - Measuring machine structures - Precision guide rods * **Electronics Manufacturing:** - Semiconductor equipment shafts - Wafer handling components - Vacuum chamber fixtures - RF waveguide supports * **Aerospace & Defense:** - Inertial guidance components - Gyroscope structural elements - Satellite instrument mounts - Avionics housing rods * **Scientific Research:** - Telescope structural members - Interferometer base rods - Cryogenic instrument shafts - Laboratory standard rods **Specialized Rod Applications:** - Precision shafting for optical systems - Thermal-stable structural components - Metrology equipment frames - Composite tooling mandrels - Alignment rod applications --- #### **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 **Quality Specifications:** - **Dimensional Standards:** ASTM A484 compliant - **Surface Quality:** Free of seams, cracks, and inclusions - **Straightness:** Per customer requirements - **Certification:** EN 10204 3.1/3.2 with full traceability --- #### **6. Processing & Manufacturing Advantages** **Machining Characteristics:** - **Turning:** 60-100 SFM with carbide tools - **Drilling:** 30-50 SFM with high-speed steel drills - **Milling:** 80-120 SFM with sharp cutters - **Threading:** Suitable for precision threads - **Surface Finish:** Excellent finish achievable **Heat Treatment:** - **Annealing Temperature:** 850-950°C (1560-1740°F) - **Stress Relieving:** 425-540°C (800-1000°F) - **Atmosphere:** Hydrogen or vacuum recommended - **Cooling Rate:** Controlled for optimal properties **Fabrication Advantages:** - **Excellent Machinability:** Good chip formation and surface finish - **Weldability:** Compatible with common welding processes - **Stability:** Maintains dimensional integrity after machining - **Consistency:** Uniform properties throughout rod length --- #### **Why Choose Our Alloy 39 Rod?** * **Premium Quality:** Strict control of chemical composition and microstructure * **Precision Manufacturing:** Excellent dimensional accuracy and surface quality * **Consistent Performance:** Reliable thermal expansion characteristics * **Technical Expertise:** Comprehensive machining and processing support * **Quality Assurance:** Full traceability with certified test reports * **Global Compliance:** Meets international standards and customer specifications **Value-Added Services:** - Precision cutting to specified lengths - Centerless grinding for tight tolerances - Heat treatment processing - Custom certification packages - Just-in-time delivery programs **Contact our technical team** for specific application requirements and engineering support. We provide complete solutions for your low expansion alloy rod needs, from material selection through machining recommendations, ensuring optimal performance in your most demanding precision 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 2756 gallon liquid totes Special package is available on request.