Nickel alloys / UNS N04405
Monel® R-405 is the free-machining version of Monel 400: a controlled sulphur addition improves machinability on automatic screw machines while keeping Monel 400's corrosion resistance.
- UNS N04405
- Spec ASTM B164
- Density 8.8 g/cm³
Also known as / equivalents
| System | Designation |
|---|---|
| UNS | N04405 |
| Also known as | Alloy R-405 |
Chemical composition
| Element | Min % | Max % |
|---|---|---|
| Ni | 63.0 | — |
| Cu | 28.0 | 34.0 |
| Fe | — | 2.5 |
| Mn | — | 2.0 |
| C | — | 0.3 |
| Si | — | 0.5 |
| S | 0.025 | 0.060 |
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.8 g/cm³ | 0.318 lb/in³ |
Available forms & specifications
| Form | Specification | Size range |
|---|---|---|
| Sheets & plates | ASTM B168, B443, B409, B424, B127, B162 | 0.3 mm – 6 mm |
| Seamless pipe & tube | ASTM B167, B444, B407, B423, B165, B161 | 1/8" – 24" NB |
| Bars & rods | ASTM B166, B446, B408, B425, B164, B160 | 3 mm – 500 mm |
| Flanges & forgings | ASTM B564 | 1/2" – 48" NB (larger on request) |
| Buttweld fittings | ASTM B366 | 1/2" – 48" NB |
Corrosion & temperature resistance
Nickel-based alloys resist caustic alkalis, chloride stress-corrosion cracking and many acids, and keep their strength and oxidation resistance at temperatures where stainless steels fail.
Applications
Monel® R-405: Valve parts, fasteners, screw-machine parts. Chemical and petrochemical plant, sour-gas and oilfield equipment, furnace and heat-treatment hardware, power generation, marine engineering and aerospace components.
Monel® R-405 vs Monel® 400
| Monel® R-405 | Monel® 400 | |
|---|---|---|
| UNS | N04405 | N04400 |
| Key property | Free-machining Monel 400 | Ni-Cu, seawater & HF resistant |
| Typical use | Valve parts, fasteners, screw-machine parts | Marine fittings, pumps, HF alkylation |
| Cr (wt %) | — | — |
| Ni (wt %) | 63.0 | 63.0 |
| Mo (wt %) | — | — |
| C (wt %) | ≤ 0.3 | ≤ 0.3 |
| Tensile / yield (min, MPa) | — | 485 / 195 |
Frequently asked questions
What is the UNS number of Monel® R-405?
Monel® R-405 is designated UNS N04405.
What is Monel® R-405 used for?
Free-machining Monel 400. Typical uses: valve parts, fasteners, screw-machine parts.
In which forms can I buy Monel® R-405 from Rajkamal Metals?
Coils & Strips, Sheets & Plates, Pipes & Tubes, Round Bars & Rods, Flanges, Buttweld Fittings, Socket Weld & Threaded Fittings, Fasteners, Ferrule / Instrumentation Fittings, Dish Ends, Custom Orders. Sizes as per standard; other sizes on request.
Do you supply a Mill Test Certificate with Monel® R-405?
Yes. Actual values are given in the Mill Test Certificate (EN 10204 3.1) supplied with each order.
What is the difference between Monel® R-405 and Monel® 400?
Monel® R-405: free-machining monel 400. Monel® 400: ni-cu, seawater & hf resistant. See the comparison table on this page.
Last updated: 30 October 2026. Grade names identify the supply range; designations are not engineering equivalents. Availability, make, origin and documentation are confirmed at quotation.
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