Skip to the main content.

Steel 18NiCrMo5

A perfect balance of strength, wear resistance and hardness. Ideal for automotive parts and heavy-duty machinery.

All uploads are encrypted end-to-end
Steel 18NICRMO5 CNC machining


  • High strength and toughness
  • Excellent fatigue resistance
  • Good machinability
  • Widely used in the aerospace and defense industries


  • Low corrosion resistance
  • More expensive than other steel varieties
  • It requires specialized welding techniques


  • Machining process: CNC machining
  • Tolerances: ISO 2768-1 fine (f) or medium (m) class. Info
  • Max size: 300 x 300 x 100 mm; 11.8 x 11.8 x 3.9 in
  • Lead time: <6 days

Rating 4.81 / 5.00

Based on 634 reviews

trusted shop logo




High strength and toughness

It is designed to withstand the most demanding applications, ensuring high performance and a long service life. Its unique properties make it ideal for automotive, aerospace and heavy machinery construction.


Excellent fatigue resistance

It offers outstanding longevity and reliability, even in the most demanding high-stress applications. Its excellent fatigue resistance makes it the ideal choice for industries where parts are subjected to repeated stress, such as automotive, heavy machinery and aerospace.


Widely used in the aerospace and defense industries

It is a material widely used in the aerospace and defense industries due to its high strength, toughness and fatigue resistance. Its excellent properties meet the requirements of these industries, ensuring reliable performance, durability and light weight.



free instant quote


Explore the extraordinary capabilities of 18NiCrMo5 steel (AISI 4317) and take your projects to new levels of excellence! This cutting-edge material has an extraordinary combination of properties that set it clearly apart from other steel alloys. With its high strength and toughness, impeccable fatigue resistance and machinability, Steel 18 offers unparalleled solutions to the most demanding challenges of modern industry. Discover how this innovative alloy can transform the way you approach your projects and satisfy your production requirements with optimal and reliable performance.


High strength and toughness: AISI 4317 has been designed to offer exceptional strength and toughness, ensuring that components can withstand the most demanding applications and harshest environments without compromising performance. Thanks to this combination of mechanical properties, this alloy is able to maintain its structural integrity even under stress, ensuring long duration and reliability in the most critical sectors of industry.

Excellent fatigue resistance: One of the distinctive features of 18NiCrMo5 steel is its exceptional fatigue resistance, making it particularly suitable for industries where components are subject to repetitive stress cycles over time. This ability to withstand alternating loads without compromising performance makes it an ideal option for applications where durability and reliability over time are crucial, allowing the risk of structural failure or failure to be minimised.

Good machinability: Thanks to its excellent machinability, 18-steel offers engineers and designers great flexibility in producing complex parts with precision and detail. This ease of machining allows stringent design requirements to be met while maintaining tight tolerances, ensuring efficient production and low costs. Furthermore, its formability allows for different shapes and geometries without compromising the material's strength and reliability, offering endless creative and functional possibilities for a wide range of industrial applications.


Low corrosion resistance: One of the limitations of 18 steel is its low corrosion resistance compared to other alloys. This vulnerability can be a problem in environments exposed to corrosive agents such as moisture, salt water or aggressive chemicals. Therefore, in applications where corrosion protection is essential, it may be necessary to use additional protective coatings or anti-corrosion treatments to preserve the integrity of the alloy.

More expensive than other steel types: Another aspect to consider is the cost of 18NiCrMo5 steel, which can be higher than other alloys available on the market. Although it offers many superior performances, this higher initial cost may be a financial consideration for some projects or applications. However, it is important to note that its superior properties and longevity often justify the additional cost in the long term, especially in situations where strength and reliability are priorities.

Best Application

Widely used in the aerospace and defence industry, steel 18 (AISI 4317) stands out for its reliable performance and superior strength. in this industry, where reliability and safety are paramount, this alloy is a preferred choice for the production of critical components. Its strength and toughness properties make it suitable for applications requiring high resistance to mechanical and environmental stresses, such as aerospace structures, transmission systems, and load-bearing components. In addition, its excellent fatigue resistance makes it ideal for applications subject to repeated load cycles, such as moving parts and control mechanisms. Thanks to its versatility and superior performance, 18NiCrMo5 steel continues to be a material of choice for critical applications in the aerospace and defence industry, contributing to the safety, reliability and performance of space systems and vehicles, and defence equipment.


In conclusion, 18 Steel emerges as a superlative option for a wide range of industrial applications due to its unique properties and superior performance. While acknowledging some limitations such as low corrosion resistance and slightly higher cost than other alloys, its unparalleled advantages in terms of strength, toughness, and fatigue resistance amply justify its use. Its versatility makes it an ideal material for industries such as aerospace and defence, where strength, reliability and performance are key requirements. By choosing 18NiCrMo5 steel, you will achieve outstanding results that will contribute to excellent designs.

"We recently partnered with Weerg to manufacture our Steel Alloy 18 (AISI 4317) components, and the results were outstanding! Weerg's precision and expertise, combined with AISI 4317 exceptional properties, produced top-notch parts. We highly recommend Weerg for your AISI 4317 manufacturing needs – a winning combination!"

alloy steel 18 PROPERTIES

Tensile breaking load 690 MPa
Modulus of elasticity 205 GPa
Elongation at break 16%
Density 7,85 g/cm³
Melting temperature 1643°C
Hardness 210 Brinell
Yield Strength 828 MPa


"Our company chose Weerg to produce our Steel Alloy 18 (AISI 4317) parts, and we couldn't be happier! The combination of Weerg's cutting-edge technology and the superior qualities of AISI 4317 resulted in high-performance components that exceeded our expectations. Weerg is the go-to choice for AISI 4317 parts – highly recommended!"



Upload your 3D file to get one step closer to manufacturing your parts.

free instant quote