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UHH armor steel: the best solution for bulletproof structures

Ultra-High Hardness (UHH) armor steel is the best performing steel alloy for protection against armor piercing (AP) bullets. Thanks to a 578 to 655 HBW hardness, UHH steel panels are able to break AP projectiles’ core and provide efficient protection with reduced weight compared to High Hard (500HB) material.

Mars® 300 is Industeel’s grade for appliqué armor, available in thickness ranging from 3 to 50 mm which can be used for a wide range of applications:

  • Individual protection, light armor for helicopter protection
  • Detachable for vehicles, add-on armor
  • Heavy protection components for main battle tanks protection against kinetic projectiles and shaped charges

Mars® 300 is also available as perforated plates with various configurations. The holes or slots are designed to interact with the diameter of the threat: when a bullet impacts the side of a hole, the incoming projectile’s core is broken or at least the projectile is deviated from its trajectory and thus its penetration capability is reduced. For the same protection level, perforated Mars® 300 is a lightweight solution equivalent to composite ceramic solutions with a much better multi-hit capability and easier integration.

Mars® 600, Industeel latest innovation, is a multipurpose UHH with an impressive ballistic behaviour in terms of deformation capability and resistance to multi-impacts combined with a workability (mainly bending) close to a 500HB steel. Its great properties suggest unlimited possibilities for add-on armor as well as vehicle structure.

Industeel UHH grades comply with the most stringent standards, including US MIL-DTL-32332 and NF A36-800. They are supplied with Industeel unequalled flatness and low internal stress and are available with tight tolerances (+0.4/+0.5) for thicknesses up to 10mm.


Industeel solutions for ballistic and blast protection applications were showcased during Eurosatory, the world leading Defense and Security Exhibition, from 11 to 15 June in Paris.

Examples of end applications made with our Ultra-High Hardness (UHH) armor steel:

APC upgraded by bolting perforated MARS® 300 panels

Truck cabin in MARS® 300 (fitted parts)

Perforated MARS® 300 as ventilation grille

Helicopter parts