According to Standards Norway; “NORSOK standards are developed by the Norwegian petroleum industry to ensure adequate safety, value adding and cost effectiveness for petroleum industry developments and operations. Furthermore, NORSOK standards are as far as possible intended to replace oil company specifications and serve as references in the authorities’ regulations.”

Hydrobolt is NORSOK M650 approved to supply super duplex stainless steel fasteners to NORSOK M630 MDS D59 & D60.

NORSOK M650 stipulates that a qualifying company has to monitor the qualification exercise. Aker Solutions is Hydrobolt’s qualifying company and due to their reputation in the industry, Hydrobolt is also listed on Equinor’s TR2000 approved manufacturer list (AML).


Why use super duplex stainless steel 32760 (F55/1.4501/MDS D59 & D60)?

Super duplex stainless steel is a material with enhanced corrosion resistance categorized by its PREN (>40) compared to duplex stainless steels which have a PREN of around 35.

Relative to other stainless steels, it gives:

  • High resistance to pitting and crevice corrosion
  • High resistance to stress corrosion cracking
  • High yield and tensile strength properties

Hydrobolt now stocks NORSOK M630 MDS D60 finished studding and nuts, as well as raw material to manufacture other fasteners as per customer requirements.

Back to Registrations