Alloy 475,Nilo 475 Bar(Round bar, Flat bar),UNS K95000,E FORU

British Specs:，American Specs:AMS 7718 Bar, Tube and Forgings MIL-N-14411 Comp 3，German Specs:

### **Alloy 475 (Nilo 475) - Round Bar & Flat Bar Product Overview** **Alloy 475**, commercially known as **Nilo 475**, is a nickel-iron-cobalt controlled expansion alloy specifically designed for matched sealing with special hard glasses and certain ceramic materials. The **Round Bar** and **Flat Bar** forms provide versatile stock material for machining components requiring unique thermal expansion compatibility in various high-reliability industrial applications. * **UNS Designation:** **K95000** * **Product Forms:** Round Bar, Flat Bar (Rectangular Bar) --- #### **1. Chemical Composition** Precisely controlled chemistry ensures consistent thermal performance in bar products. | Element | Percentage (%) | Role in the Alloy | |:---|:---|:---| | **Nickel (Ni)** | 46.0 - 48.0 | Primary element controlling CTE characteristics | | **Cobalt (Co)** | 24.0 - 26.0 | Modifies thermal expansion properties | | **Iron (Fe)** | Balance | Base structural element | | **Manganese (Mn)** | 0.10 - 0.30 | Enhances hot workability during bar production | | **Silicon (Si)** | 0.10 - 0.30 | Improves glass wetting and sealing performance | | **Carbon (C)** | 0.05 max | Limited for optimal machinability and ductility | | **Sulfur (S)** | 0.02 max | Controlled impurity | | **Phosphorus (P)** | 0.02 max | Controlled impurity | --- #### **2. Physical Properties** Optimized properties for bar applications and special glass/ceramic sealing. | Property | Value / Condition | Notes | |:---|:---|:---| | **Density** | 8.35 g/cm³ (0.302 lb/in³) | Higher density due to cobalt content | | **Melting Point** | ~1445 °C (2635 °F) | | | **Thermal Expansion Coefficient** | 20-300°C: 7.8-8.5 μm/m·°C
20-400°C: 8.2-9.0 μm/m·°C | Unique CTE for special applications | | **Curie Temperature** | ~420 °C (790 °F) | Modified by cobalt addition | | **Thermal Conductivity** | 14.5 W/m·K at 20°C | | | **Electrical Resistivity** | 0.52 μΩ·m at 20°C | | | **Specific Heat** | 0.45 J/g·°C at 20°C | | --- #### **3. Mechanical Properties (Annealed Condition)** **Round Bar Properties:** * **Tensile Strength:** 540-610 MPa (78-88 ksi) * **Yield Strength (0.2% Offset):** 300-370 MPa (44-54 ksi) * **Elongation:** 25-35% in 2 inches * **Reduction of Area:** 40-55% * **Hardness:** 75-90 HRB * **Modulus of Elasticity:** 158 GPa (22.9 × 10⁶ psi) **Flat Bar Properties:** * **Tensile Strength:** 530-600 MPa (77-87 ksi) * **Yield Strength:** 290-360 MPa (42-52 ksi) * **Elongation:** 20-30% in 2 inches * **Hardness:** 73-88 HRB --- #### **4. Product Specifications & Applications** **Round Bar Specifications:** * **Diameter Range:** 3.0 mm to 300 mm * **Diameter Tolerance:** ±0.1 mm (<25 mm), ±0.2% (>25 mm) * **Straightness:** ≤1 mm per meter * **Surface Finish:** 3.2 μm Ra standard, 1.6 μm Ra available **Flat Bar Specifications:** * **Thickness Range:** 3.0 mm to 100 mm * **Width Range:** 10 mm to 300 mm * **Thickness Tolerance:** ±0.15 mm (<10 mm), ±1.5% (>10 mm) * **Width Tolerance:** ±0.5 mm (<50 mm), ±1.0% (>50 mm) **Primary Applications:** **Round Bar Applications:** * **Precision Machined Components:** Electrode pins and support posts for special glass systems * **Hermetic Feedthroughs:** Single and multi-pin connectors for specialized systems * **Ceramic Sealing Components:** Parts for ceramic-to-metal seal applications * **Optical Mounts:** Lens barrels and positioning components in advanced instruments * **Vacuum System Components:** Specialized flanges and connectors **Flat Bar Applications:** * **Specialized Flanges:** Mounting surfaces for unique glass-to-metal assemblies * **Structural Frameworks:** Support elements requiring specific CTE matching * **Base Plates:** Thermally compatible mounting platforms for special applications * **Machined Headers:** Multi-pin connector bases for specialized electronic packages * **Instrumentation Components:** Precision frames and mounting brackets --- #### **5. International Standards** Comprehensive international specifications for bar products. | Standard Type | Standard Number | Title / Specification | |:---|:---|:---| | **ASTM** | **ASTM F15** | Standard Specification for Iron-Nickel Sealing Alloys | | **UNS** | **K95000** | Unified Numbering System Designation | | **AMS** | AMS 7724 | Aerospace Material Specification | | **ASTM** | ASTM B48 | Standard Specification for Rod and Bar | | **DIN** | DIN 1745 | Metallic Materials for Glass-to-Metal Seals | | **ISO** | ISO 9711 | Metallic Materials for Glass-to-Metal Seals | --- #### **6. Manufacturing & Processing** **Machining Characteristics:** * **Machinability Rating:** 35% (compared to 12114 steel) * **Recommended Tools:** Carbide or high-speed steel with positive rake angles * **Cutting Speeds:** 25-40 m/min for turning, 20-30 m/min for milling * **Feed Rates:** 0.1-0.3 mm/rev for turning, 0.05-0.15 mm/tooth for milling * **Coolant Requirements:** Essential for optimal tool life and surface finish **Heat Treatment:** * **Annealing:** 850-900°C in hydrogen or vacuum atmosphere * **Stress Relieving:** 650-750°C after heavy machining operations * **Cooling Rate:** Controlled cooling ≤100°C per hour through critical range **Surface Preparation for Sealing:** * **Cleaning:** Degreasing and pickling to remove contaminants * **Plating Options:** Copper (1-3 μm) for improved wetting characteristics * **Pre-oxidation:** Controlled oxidation at 800-900°C in air atmosphere * **Surface Finish:** 0.8-3.2 μm Ra optimal for glass/ceramic adherence --- #### **7. Quality Assurance** * **Chemical Certification:** Mill certificate with heat analysis * **Dimensional Verification:** Statistical process control for size and straightness * **Surface Quality:** Visual inspection and surface roughness measurement * **Mechanical Testing:** Tensile and hardness testing per ASTM E8 and E18 * **Metallurgical Examination:** Grain size assessment per ASTM E112 * **Traceability:** Full material traceability from melt to final product --- **Summary** **Alloy 475 (Nilo 475) Round Bar and Flat Bar (UNS K95000)** provide essential stock materials for manufacturing precision components requiring reliable sealing with special glasses and certain ceramics. Their unique thermal expansion properties, enhanced by cobalt content, combined with good machinability and consistent quality, make them indispensable for specialized applications in aerospace, medical devices, scientific instrumentation, and advanced industrial equipment. The availability in both round and flat bar forms offers design flexibility for various component geometries while maintaining the critical thermal expansion matching with special materials. Compliance with **ASTM F15** and other international standards ensures consistent material performance and reliability in demanding applications where hermetic integrity and precise thermal expansion control are paramount.

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 2523 gallon liquid totes Special package is available on request.