MONEL Alloy R-405,Monel Nickel-Copper Alloy, UNS N04405; ，1

### **Product Introduction: MONEL® Alloy R-405 (UNS N04405)** **MONEL® Alloy R-405** is a free-machining variant of the classic MONEL Alloy 400. Its composition is almost identical to Alloy 400, with the deliberate addition of a controlled amount of sulfur to significantly improve machinability. This modification allows it to be machined at high speeds, producing small, broken chips, which results in superior surface finishes and longer tool life. The "R" in the name historically designated a "resulturized" grade. While it offers excellent machinability, the added sulfur slightly reduces its ductility and hot workability compared to Alloy 400. It is primarily selected for applications requiring extensive machining of parts that will be used in corrosive environments. --- ### **International Standards & Material Equivalents** MONEL Alloy R-405 is covered by major international standards, often listed alongside Alloy 400 with a note on its sulfur content. | Standard Type | Standard Number | Designation | | :--- | :--- | :--- | | **UNS (USA)** | **N04405** | **MONEL Alloy R-405** | | **ASTM (USA)** | B164 | Rod and Bar | | **ASTM (USA)** | B165 | Seamless Pipe and Tube | | **ASME (USA)** | SB-164 | Rod and Bar (Pressure Vessel Code) | | **DIN (Germany)** | 17760 | NiCu30FeS | | **Werkstoff Nr.** | **2.4375** | **2.4375** | | **AFNOR (France)** | NU 30 | | > **Note:** MONEL® is a registered trademark of Special Metals Corporation. The key identifier is **UNS N04405** and **Werkstoff 2.4375**. --- ### **Chemical Composition** The composition is distinguished from MONEL 400 by its controlled sulfur content, which forms sulfide inclusions that break up chips during machining. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 63.0 min. | | **Copper (Cu)** | 28.0 - 34.0 | | **Iron (Fe)** | 2.5 max. | | **Manganese (Mn)** | 2.0 max. | | **Carbon (C)** | 0.3 max. | | **Silicon (Si)** | 0.5 max. | | **Sulfur (S)** | **0.025 - 0.060** *(The defining characteristic)* | --- ### **Physical Properties** The physical properties of Alloy R-405 are nearly identical to those of Alloy 400. | Property | Value | | :--- | :--- | | **Density** | 8.80 g/cm³ (0.318 lb/in³) | | **Melting Point** | 1350 °C (2460 °F) | | **Thermal Conductivity** | 22 W/m·K (at 20°C) | | **Electrical Resistivity** | 0.51 μΩ·m (at 20°C) | | **Modulus of Elasticity** | 179 GPa (26 x 10⁶ psi) | | **Magnetic Response** | Essentially non-magnetic at ambient temperatures | --- ### **Mechanical Properties (Typical for Hot-Rolled & Annealed Condition)** The addition of sulfur slightly reduces ductility and impact strength compared to the sulfur-free Alloy 400. | Property | Value (Hot-Rolled & Annealed) | | :--- | :--- | | **Tensile Strength** | 550 MPa (80 ksi) | | **Yield Strength (0.2% Offset)** | 240 MPa (35 ksi) | | **Elongation** | **35%** (Lower than Alloy 400's 40%) | | **Hardness (Rockwell B)** | 65 - 75 HRB | --- ### **Key Characteristics & Advantages** 1. **Excellent Machinability:** The primary advantage. It has a machinability rating of approximately **50%** (based on a scale where AISI 1212 steel = 100%), which is a significant improvement over the unruly, long chips produced by Alloy 400. This allows for higher production rates and better surface finishes. 2. **Good Corrosion Resistance:** Retains much of the excellent corrosion resistance of MONEL 400, making it suitable for a wide range of corrosive environments, including: * Seawater and brackish water * Hydrofluoric acid (in various concentrations and temperatures) * Alkaline solutions * Sulfuric and hydrochloric acids under reducing conditions 3. **High Strength:** Maintains the good mechanical strength of the nickel-copper system. 4. **Trade-offs:** The improved machinability comes with minor trade-offs: * **Reduced Ductility:** Not recommended for severe cold-forming operations. * **Not for Hot Working:** The sulfur content makes it susceptible to hot cracking; it is not suitable for forging or hot rolling. * **Reduced Weldability:** Welding is generally not recommended as the sulfur can cause solidification cracking. Parts are typically used in the as-machined condition. --- ### **Product Applications** MONEL Alloy R-405 is specified for applications requiring complex machining of components that must withstand corrosion. * **Fasteners and Fittings:** * Bolts, nuts, studs, screws, and pipe plugs. * Valve stems and seats in marine and chemical service. * **Pump and Valve Components:** * Shafts, impellers, bushings, and valve trim for use in seawater and chemical pumps. * **Machine Parts:** * Gears, chain driver parts, and other heavily machined components for corrosive environments. * **Oil & Gas:** * Wellhead components, downhole tool parts, and manifold fittings. ### **Summary** **MONEL Alloy R-405 (UNS N04405 / Werkstoff 2.4375)** is the free-machining version of MONEL 400, specifically engineered for high-volume production of parts requiring extensive machining. Its defining characteristic is the controlled addition of **sulfur (0.025-0.060%)**, which dramatically improves chip-breaking and tool life. While it sacrifices some ductility and weldability, it retains the excellent corrosion resistance and strength of the MONEL family, making it an ideal choice for machined components like fasteners, pump parts, and valve stems destined for service in seawater, chemicals, and other aggressive media.

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 3293 gallon liquid totes Special package is available on request.