Understanding Norsok M-650

By Ingve Stangeland, Technical Manager, MRC Global
May 18, 2017 Tags: NORSOK, NORSOK 650
MRC Global Ingve Stangeland
Ingve Stangeland

If you are involved in sourcing products for offshore or subsea applications, you have probably been introduced to the Norsok M-650 qualification.

So, what is Norsok?

Prior to 1994, each individual oil company, and/or engineering company, had their own set of material requirements for the “same” type of materials to be produced and delivered to a project in the Norwegian sector. Further, the same oil company and/or engineering company, could have a different set of requirements for any prior or later projects.

To help standardize processes and create uniform product requirements, the Norsok set of specifications were created in the 1990s. They are managed by Standards Norway on behalf of the various Norwegian industry participants.

As an addition to typical “material” Norsok specifications, a “qualification” specification named M-650 was also established to ensure improved quality verification for critical materials. While Norsok M-650 began as a manufacturing qualification specific to the Norwegian offshore industry, it has become a trusted certification around the world as many large end users have begun to rely on the qualification across their global operations.

The M-650 qualification

M-650 qualification identifies minimum requirements for a manufacturer’s production route, where the main focus is typically on the following issues:

  • Hot forming, welding and heat treatment of final products – to ensure satisfactory material properties
  • Test sampling location to verify material properties in final product
  • Traceability control – from incoming raw material up to final marking and packing
  • Manufacturer personnel knowledge and understanding of the M-650 requirements
  • Suitable equipment and experience to produce applicable materials and products
  • General process control – verified and documented in a Manufacturing Summary


Material types with mandatory qualification to Norsok M-650 include but are not limited to several duplex and austenitic stainless steels that typically deliver both high strength and excellent corrosion resistance in harsh offshore applications.

Each grade and manufacturing process requires an individual qualification process, including sacrificial testing of final products. It is not an easy qualification to achieve but it helps to ensure that a manufacturer’s production route is capable of reliably producing quality products over time.


How do I get in?

If there are several routes, each of these will require a separate qualification process. A manufacturer of flanges or fittings could have 15 to 20 various routes to be qualified for the above material grades. It is not an easy qualification to achieve but it helps to ensure that a manufacturer’s production route is capable of reliably producing quality products over time.

How do I get in?

There is not a set governing body that issues qualification certifications or publishes a list of approved manufacturers. A committee of experts works together to constantly maintain and update the specifications but, the Norsok M-650 specification allows any organization, as long as they meet some conditions, to perform qualifications of manufacturers. The standard states that the qualifying organization needs to be acknowledged by the purchaser/end user.

MRC Global is a recognized qualifying organization– especially in the Norwegian market.

MRC Global are member of the Norsok M-650 committee, and have performed numerous qualifications of manufacturers of pipes, fittings and flanges in the past 15 years. If you have more detailed questions about the Norsok approval process, please contact us. We would be happy to help you identify reliable sources for these important products.

About the Author

Ingve Stangeland has been part of MRC Global since 1998. In his current role as a technical manager, he enjoys meeting and working with skilled people to further understand technical issues that arise when helping our customers bring energy to the world every day. He is a qualified metallurgist and engineer and represents MRC Global on the Norsok M-650 Committee.