Alloy 455，Custom 455 Bar(Round bar, Flat bar)，UNS S45500，EFORU

British Specs:，American Specs:AMS 5617 Bar and Forgings AMS 5860 Sheet, Strip and Plate，German Specs:

### **Alloy 455 / Custom 455 Bar (Round Bar & Flat Bar) - UNS S45500** **Overview** **Alloy 455**, commercially known as **Custom 455**, is a premium martensitic precipitation-hardening stainless steel that offers an exceptional combination of ultra-high strength, good corrosion resistance, and excellent toughness. **Custom 455 Bar** products, including both **round bars** and **flat bars**, provide these superior properties in forms ideal for machining, fabrication, and structural applications requiring maximum strength and reliability in demanding environments. The UNS **S45500** designation identifies this specific precipitation-hardening stainless steel composition. Custom 455 bars are particularly valued for applications requiring high strength-to-weight ratios, dimensional stability during heat treatment, and good corrosion resistance comparable to standard austenitic stainless steels. --- ### **Chemical Composition** | Element | Content (%) | | :--- | :--- | | **Iron (Fe)** | Balance | | **Chromium (Cr)** | 11.0 - 12.5 | | **Nickel (Ni)** | 7.5 - 9.5 | | **Copper (Cu)** | 1.5 - 2.5 | | **Niobium (Nb)** | 0.1 - 0.5 | | **Titanium (Ti)** | 0.8 - 1.4 | | **Manganese (Mn)** | 0.50 (Max) | | **Silicon (Si)** | 0.50 (Max) | | **Carbon (C)** | 0.05 (Max) | | **Phosphorus (P)** | 0.04 (Max) | | **Sulfur (S)** | 0.03 (Max) | **Key Feature:** The balanced composition creates a precipitation-hardenable martensitic structure capable of achieving tensile strengths exceeding 1550 MPa (225 ksi) after proper heat treatment, while maintaining good corrosion resistance. --- ### **Physical Properties** | Property | Value | | :--- | :--- | | **Density** | 7.76 g/cm³ (0.280 lb/in³) | | **Melting Point** | 1400-1440°C (2550-2625°F) | | **Electrical Resistivity** | 85 μΩ·cm at 20°C | | **Thermal Conductivity** | 18.5 W/m·K at 20°C | | **Thermal Expansion Coefficient** | 10.1 μm/m·°C (20-100°C) | | **Magnetic Permeability** | Magnetic after heat treatment | --- ### **Mechanical Properties** Typical mechanical properties for Custom 455 bar after heat treatment: | Condition | Tensile Strength | Yield Strength (0.2% Offset) | Elongation (%) | Hardness (Rockwell C) | | :--- | :--- | :--- | :--- | :--- | | **Solution Treated** | 1000-1200 MPa (145-175 ksi) | 950-1100 MPa (140-160 ksi) | 10-15 | 25-32 | | **H900 Aged** | 1550-1750 MPa (225-255 ksi) | 1450-1650 MPa (210-240 ksi) | 6-10 | 44-48 | | **H1000 Aged** | 1400-1600 MPa (200-230 ksi) | 1300-1500 MPa (190-220 ksi) | 8-12 | 40-44 | | **H1050 Aged** | 1250-1450 MPa (180-210 ksi) | 1150-1350 MPa (170-195 ksi) | 10-14 | 36-40 | --- ### **International Standards** | Standard Organization | Standard Number | Specification | | :--- | :--- | :--- | | **ASTM** | ASTM A564/A564M | Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes | | **AMS** | AMS 5617 | Precipitation Hardening Stainless Steel Bars and Forgings | | **ASME** | SA-564 | Age-Hardening Stainless Steel Bars for Pressure Vessels | | **UNS** | S45500 | Alloy 455 | | **ASTM** | ASTM A108 | Steel Bars, Carbon, Cold-Finished | | **AMS** | AMS 2759/3 | Heat Treatment of Steel Parts | --- ### **Product Specifications** **Round Bar Specifications:** - **Diameter Range:** 1/8" to 12" (3mm to 300mm) - **Length:** Standard 12' to 20' (3.6m to 6m) - **Tolerances:** Hot rolled ±1%, Cold drawn ±0.005", Centerless ground ±0.0005" - **Surface Finish:** Hot rolled, turned, cold drawn, centerless ground **Flat Bar Specifications:** - **Thickness:** 1/8" to 4" (3mm to 100mm) - **Width:** 1/2" to 12" (12mm to 300mm) - **Length:** Standard 10' to 20' (3m to 6m) - **Tolerances:** Standard mill tolerances or precision machined **Available Conditions:** - Solution Treated (Condition A) - Solution Treated and Aged (Various tempers) - Hot Rolled - Cold Drawn - Centerless Ground --- ### **Heat Treatment** **Solution Treatment:** - Temperature: 815-830°C (1500-1525°F) - Time: 30 minutes per inch of thickness - Cooling: Air cool or faster - Result: Soft condition for machining (RC 25-32) **Aging Treatments:** - **H900:** 480°C (900°F) for 4 hours, air cool - **H950:** 510°C (950°F) for 4 hours, air cool - **H1000:** 540°C (1000°F) for 4 hours, air cool - **H1050:** 565°C (1050°F) for 4 hours, air cool --- ### **Product Applications** **Round Bar Applications:** - Aircraft landing gear components - High-strength shafts and axles - Pump shafts and valve stems - Military vehicle components - Machinery spindles and arbors - Fasteners and special bolts **Flat Bar Applications:** - Structural supports and brackets - Machine frames and bases - Wear plates and guides - Tooling plates and fixtures - Specialized structural members - Processing equipment components **Aerospace Industry:** - Airframe components - Missile and rocket parts - Engine mounts and brackets - Actuator components - Structural fittings **Defense Applications:** - Firearm components - Armor system parts - Military hardware - Weapon system mechanisms - Defense vehicle parts **Industrial Equipment:** - High-strength machine components - Processing equipment parts - Material handling components - Special tooling applications - Precision machinery parts **Medical Devices:** - Surgical instrument components - Medical equipment parts - Orthopedic device components - Dental instrument parts --- ### **Machining & Fabrication** **Machinability:** - Best machined in solution-treated condition (RC 25-32) - Machinability rating: 45% (compared to 1212 steel) - Requires rigid setups and positive rake tools - Recommended tool materials: Carbide or high-speed steel **Recommended Machining Parameters:** - **Turning Speed:** 60-100 SFM - **Milling Speed:** 80-120 SFM - **Drilling Speed:** 30-50 SFM - **Feed Rates:** 0.005-0.015 inches per revolution - **Coolant:** Water-soluble oils recommended **Fabrication Characteristics:** - Can be welded using matching filler metal - Best formed in solution-treated condition - Good grindability and EDM characteristics - Suitable for various finishing operations --- ### **Key Advantages** - **Ultra-High Strength:** Capable of achieving yield strengths over 1450 MPa (210 ksi) - **Excellent Strength-to-Weight Ratio:** Ideal for weight-critical applications - **Good Corrosion Resistance:** Superior to most martensitic stainless steels - **Simple Heat Treatment:** Single-step aging process after fabrication - **Dimensional Stability:** Minimal distortion during heat treatment - **Excellent Toughness:** Good combination of strength and fracture toughness - **Versatile Product Forms:** Available in round and flat bar configurations **Design Considerations:** - Maximum service temperature: 425°C (800°F) - Not recommended for prolonged exposure above 425°C - Suitable for cryogenic applications - Good resistance to stress corrosion cracking - Magnetic after heat treatment --- ### **Quality Assurance** **Testing and Certification:** - Chemical analysis certification - Mechanical testing verification - Hardness testing - Ultrasonic testing (as required) - Dimensional verification - Surface quality inspection **Certification Standards:** - ASTM A564 requirements - AMS 5617 specifications - Customer-specific requirements - Full traceability documentation Custom 455 Bar (Round & Flat), UNS S45500 represents a premium precipitation-hardening stainless steel that provides an outstanding combination of ultra-high strength, good corrosion resistance, and excellent mechanical properties in versatile bar forms. Its superior characteristics make it particularly valuable for aerospace, defense, medical, and industrial applications where maximum strength, reliability, and precision manufacturing capabilities are critical requirements.

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 1691 gallon liquid totes Special package is available on request.