L-605® is a cobalt-chromium-tungsten-nickel alloy that is highly resistant to corrosion. It is produced by following vaccum induction melting (VIM) with an electroslag remelt (ESR) to remove impurities. It is also considered nonmagnetic in all conditions.

A Tungsten content of 15% leaves L-605® radiopaque, making it an ideal material for medical implant devices where radiopacity is important.

Common uses include:

  • Artificial Heart Valves
  • Fracture fixation
  • Hip Implants
  • Stent Applications

This alloy is also known as:

  • Haynes 25®
  • UNS R30605
  • UNS R30605

Chemical Data, Mechanical Data and Specifications for L-605 Cobalt Chrome.


Chemical Range for L-605®
Element Minimum Maximum
Carbon 0.05 0.15
Chromium 19.0 21.0
Cobalt Balance --
Iron -- 3.00
Manganese 1.00 2.00
Nickel 9.00 11.00
Phosphorus -- 0.030
Silicon -- 0.40
Sulphur -- 0.030
Tungsten 14.00 16.00


Typical Mechanical Properties for L-605®
Form Tensile Strength Yield Strength Elongation at Break
Annealed 133 ksi 69 ksi 41%
Cold Worked 30% 195 ksi 145 ksi 16%


Applicable Specifications
Rod AMS 5759, ASTM F90
UNS R30605

L-605 and Haynes 25 are registered trademarks of their respective owners.