MR0175 The Standard

About MR0175/ISO 15156

MR0175 is a federally mandated standard in the United States and is globally recognized as ISO 15156. MR0175/ISO 15156 addresses requirements and recommendations for selecting and qualifying materials for H2S service in oil and natural gas production. MR0175 addresses all forms of cracking caused by H2S and applies to equipment using conventional elastic design criteria.

The standard addresses requirements and recommendations for selecting and qualification carbon and low-alloy steels, corrosion-resistant alloys, and other alloys for service in equipment used in oil and natural gas production and natural gas treatment plants in H2S-containing environments.

It is also the most complex and misunderstood standard. Compendiums of interpretations, areas of opinion, lists of corrections, and updates are issued regularly. This creates dated and conflicting information in the marketplace, but AMPP offers instruction from the world’s leading industry experts.

Document Structure

Part 1, General principles for the selection of cracking-resistant materials

Part 2, Cracking-resistant carbon and low alloy steels, and the use of cast irons

Part 3, Cracking-resistant CRAs (corrosion-resistant alloys) and other alloys

Sulfide Stress Cracking (SSC), Stress Corrosion Cracking (SCC)

MR0175 is currently in English, French, Chinese, and Spanish.

Not intended for refinery equipment (NACE Standard MR0103 should be used).

Stay up to date between edits. Visit

  • This site has numerous questions and responses that have accumulated since the publish date of the standard.
  • Maintenance Panel addresses questions and then the responses are compiled into a library.

Download the standard or become an AMPP member.


The purpose of ANSI/NACE MR0175/ISO 15156 is to:

  • Avoid costly equipment failures
  • Minimize the health and safety risk to the public, personnel, and the environment
  • Protect metallic components from
  • Sulfide stress cracking, stress corrosion cracking, and other mechanisms of cracking caused by H2S.

The responsibility for the safe application of alloys is defined as follows:

Manufacturers and suppliers provide materials that meet:

  • NACE MR0175 minimum metallurgical requirements
  • chemistry, mechanical properties, hardness, and processing
  • USER - specified additional metallurgical requirements

Users are responsible for the materials selection and defining the environment

  • Oil company
  • Contractor (if delegated)
  • Service (if delegated)
  • NOT the manufacturer or supplier (materials and components).