- Grade / Alloy
- X4CrNiMo16-5-1
- EN / W.Nr.
- 1.4418X4CrNiMo16-5-1
- AISI / SAE
- —
- UNS
- —
- Family
- Martensitic
Chemical composition
Chemical composition
Composition limitsComposition limits for long products within EN 10088-3.
| Element | Content (% by mass) |
|---|---|
| CCarbon | ≤ 0.06 |
| SiSilicon | ≤ 0.7 |
| MnManganese | ≤ 1.5 |
| PPhosphorus | ≤ 0.04 |
| SSulfur | ≤ 0.03 |
| NNitrogen | ≤ 0.02 |
| CrChromium | 15–17 |
| MoMolybdenum | 0.8–1.5 |
| NiNickel | 4–6 |
Values describe the grade, not the analysis of a specific batch. The applicable product specification and material certificate determine acceptance. A dash does not mean zero.
Loaded stainless components
1.4418 is a low-carbon martensitic stainless steel for heavily loaded mechanical components. Its nickel- and molybdenum-bearing composition is used in shafts and bodies where toughness matters alongside strength. Its role centres on force-transmitting or pressure-exposed parts rather than hard cutting edges, giving it a different application profile from high-carbon blade steels.
What toughness adds
Toughness describes the ability to absorb energy before fracture. In pump shafts and similar moving components, loads are not always constant: their direction or magnitude may change during service. 1.4418 is used where this response matters alongside high strength. Corrosion resistance accompanies these mechanical characteristics in components exposed to fluids.
Pumps, valves and energy equipment
Pump shafts, valve parts, compressor components and hydropower equipment illustrate its use. The grade is familiar in parts that perform a mechanical function while encountering water or other fluids. Certain marine shaft applications also use it. The combination of stainless behaviour, load-carrying capability and toughness is central to these applications.
Distinct from high-carbon martensitic grades
Many grades in the 420 and 440 families serve parts where high hardness and wear resistance are priorities. The lower-carbon, nickel-bearing composition of 1.4418 instead emphasises strength and toughness in loaded components. This mechanical character also distinguishes it from austenitic 316L in general corrosion service. Shafts, pump components and mechanical bodies are representative applications.
Typical application areas
Pump shafts, valves, turbine and machinery components.
Product and cutting options
Relevant product forms for this material are listed below. Availability varies with grade and dimensions.