Armox armor steel is among the absolute top-tier protective materials. Developed by the Swedish company SSAB, this material is synonymous with extreme toughness and hardness. However, these very properties, which make it a bulletproof barrier, represent a significant challenge for mechanical processing. How, then, can it be processed while maintaining its ballistic integrity?
Unlike conventional structural steels, Armox is primarily optimized to absorb the impact energy of a projectile through a combination of high hardness and controlled toughness. Consequently, the method of its technological processing has a fundamental impact on the final ballistic properties. In the CNC machining and EDM wire cutting of Armox armor steel, the goal is not merely dimensional precision, but above all, the preservation of the material’s metallurgical integrity.
Microstructure of Armox and Material Behavior Under Mechanical Loading
Armox is supplied in a fine-grained martensitic condition, providing:
- high surface hardness (approximately 400–600 HBW depending on grade)
- ability to plastically absorb impact energy
- high resistance to localized penetration
Improper thermal or mechanical influence leads to tempering of martensite, reduction of surface hardness, and formation of residual stresses. These effects directly reduce ballistic effectiveness, making strict technological discipline during processing absolutely critical.
Cutting of Armox Armor Steel – Influence of Technology on Microstructure
The selected cutting technology directly determines whether Armox retains its protective properties or undergoes degradation.
Thermal Technologies – Laser and Plasma
During laser and plasma cutting, localized heating above transformation temperatures occurs, forming a heat-affected zone (HAZ) in which:
- martensitic microstructure decomposes
- hardness is significantly reduced
- residual stresses are introduced
Although these are fast and economical methods, they represent potential weakening of armor performance for ballistic applications.
Waterjet Cutting
Waterjet cutting represents the technologically highest-quality method for dividing Armox armor steel:
- no thermal influence on the material
- complete preservation of original microstructure
- zero degradation of hardness and toughness
Because neither overheating nor mechanical loading occurs, ballistic properties remain fully preserved. From a technological standpoint, this is the most expensive cutting method, but also the safest for critical armor components.
EDM Wire Cutting
EDM cutting is a highly precise alternative for dividing hardened armor steels, where material is removed by electrical discharge erosion without mechanical forces.
The result is:
- minimal thermal influence limited to a micrometer-scale surface layer
- preservation of core material hardness
- zero mechanical stresses
With properly selected EDM parameters, the ballistic integrity of Armox remains virtually unaffected, making this technology ideal for precise contours and complex armor component geometries.
CNC Machining of Armox – Extreme Cutting Conditions and Controlled Processing
CNC machining of Armox armor steel ranks among the most demanding processes in precision engineering. The high hardness generates extreme cutting forces and rapid tool wear.
During machining, the following occur:
- plastic deformation of the surface layer
- localized work hardening
- formation of residual stresses
Therefore, the process requires specialized carbide or CBN tooling, low feed rates, high-pressure cooling, and extremely rigid CNC machines.
Importance of 3-Axis and 5-Axis CNC Machining
3-axis CNC machining of Armox is mainly used for:
- precision holes
- planar surfaces
- functional joints
5-axis CNC machining of Armox armor steel enables:
- production of complex geometries in a single setup
- higher geometric accuracy
- reduced residual stresses
- more consistent surface quality
For ballistic and security applications, this represents the most technologically precise method of machining hardened steel.
Conclusion – Armor Precision Is Defined by EDM and CNC Technologies
With Armox armor steel, the true quality of the finished component is determined not only by the material itself, but primarily by the processing technology.
EDM wire cutting of Armox enables division of extremely hard ballistic steel with maximum precision, without mechanical loading and with minimal thermal influence. CNC machining of Armox armor steel—particularly using 3-axis and 5-axis CNC systems—then allows the creation of precise functional features while maintaining the material’s mechanical and protective properties.
At CDL, we focus long-term on precision EDM cutting and CNC machining of armor materials. Experience with hardened ballistic steel such as Armox allows preservation of both geometric accuracy and functional ballistic performance of the components.
With armor steel, it is not only the hardness of the material that matters — it is the entire technological process.
