BUMAX® ULTRA is the strongest fastener on the market and is frequently used to replace high strength carbon steel fasteners in critical applications.

The strongest fastener on the market – and it is stainless

BUMAX® ULTRA achieves its super high strength from unique strain hardening and precipitation hardening manufactured using Nobel Prize winning Quasi-Crystalline Precipitate technology. This method has been specifically designed for applications where ultra-high strength combined with high ductility is required in the final product.

The very high strength to weight ratio in combination with good formability and ductility make it a very attractive fastener alternative to other lightweight materials, e.g. Titanium. BUMAX® ULTRA also has a corrosion resistance comparable with 316L (A4) and can be used at service temperatures between -50 and 400°C with retained mechanical properties.

BUMAX Ultra Data Sheet

Advanced engineering grade for extreme applications

Despite being a stainless steel, BUMAX® ULTRA is frequently used to replace high strength carbon steel fasteners in critical applications with extreme requirements on strength and ductility.

All fasteners in BUMAX® ULTRA are custom made to meet the requirements of individual applications and can be delivered with different mechanical properties, with a tensile strength exceeding 1,700 MPa. BUMAX® ULTRA is an advanced engineering grade and BUMAX provides close technical support in order to develop an end solution that fully meets customer requirements.


  • Extreme strength– providing opportunities to downsize and design new lightweight options at lower cost.
  • Excellent weight to strength ratio.
  • Excellent fatigue and ductility properties– despite its high tensile strength, BUMAX® ULTRA offers excellent fatigue and ductility properties compared with other high strength fastener materials.
  • Good corrosion resistance– in most environments, comparable with 316L (A4).
  • Low thermal expansion.
  • Retained mechanical properties– at elevated temperatures.
  • Excellent relaxation properties.
  • All our products offer full traceability.

Benefits of high strength fasteners

  • Reduced size and weight.
  • Reduced number of fasteners needed.
  • Smaller screw joints.
  • Compact designs.
  • Increased clamping force.
  • Increased safety.


UNS: S46910


Contact us to find out more about BUMAX® Ultra, and how the grade can benefit your applications.

BUMAX is available worldwide

Our extensive network of sales offices and distributors makes it easy to get in touch with us. Find your local sales office or distributor below. For other countries not represented, please contact our Main Sales Office.

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