NACE MR0175 / ISO 15156
Materials for use in H₂S-containing environments in oil and gas production
Sets the requirements for metallic materials used in oil and gas production equipment exposed to H₂S (sour service), to resist sulphide stress cracking and stress-corrosion cracking.
- Quality & service
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is NACE MR0175 / ISO 15156?
NACE MR0175 / ISO 15156 sets the requirements for metallic materials used in H₂S-containing (sour) environments in oil and gas production. Part 1 gives general principles, Part 2 covers carbon and low-alloy steels and cast irons, and Part 3 covers corrosion-resistant alloys such as stainless, duplex and nickel alloys. Compliance depends on grade, heat treatment, hardness and the service conditions — it is not a property of the grade name alone.
NACE MR0175 / ISO 15156 at a glance
| Part 1 | General principles for selecting cracking-resistant materials |
|---|---|
| Part 2 | Carbon and low-alloy steels, cast irons — hardness limits (values pending current standard text) |
| Part 3 | Corrosion-resistant alloys — limits by temperature, H₂S partial pressure, chloride and pH |
| Refinery service | NACE MR0103 / ISO 17945 covers sour refinery environments |
How to write NACE MR0175 / ISO 15156 on a purchase order
Name the product, size, material specification and grade, the dimensional standard and the certificate. An example line:
Illustrative only — sizes, tests, inspection level and any project values come from your purchase specification.
NACE MR0175 / ISO 15156 edition and verification status
Which edition we have confirmed, and what is still being checked before any numerical requirement is published here.
| Current edition | Not yet confirmed against the publisher listing |
|---|---|
| Full-text verification | In progress — numerical requirements are not published on this page |
| Edition on your order | The edition named in your purchase order or design code governs — confirm it with your enquiry |
What to know before ordering to NACE MR0175 / ISO 15156
The points that decide whether material to NACE MR0175 / ISO 15156 is accepted at inspection.
- Each alloy family has hardness and environmental limits; compliance is material- and condition-specific.
- Duplex, 825, 625 and C276 each have their own tables of acceptable conditions.
- Ask for the compliance statement on the certificate when you order.
How NACE MR0175 / ISO 15156 fits into an order
A purchase order line is only complete when it names the material standard, the dimensional standard and the inspection document. Miss one and the mill, the inspector and the buyer can each read the order differently.
Standards used with NACE MR0175 / ISO 15156
Same family
NACE MR0175 / ISO 15156 — questions buyers ask
What is NACE MR0175 / ISO 15156?
NACE MR0175 / ISO 15156 sets the requirements for metallic materials used in H₂S-containing (sour) environments in oil and gas production. Part 1 gives general principles, Part 2 covers carbon and low-alloy steels and cast irons, and Part 3 covers corrosion-resistant alloys such as stainless, duplex and nickel alloys. Compliance depends on grade, heat treatment, hardness and the service conditions — it is not a property of the grade name alone.
What does "NACE compliant" mean for a pipe or flange?
That the material, heat treatment and hardness meet the limits of MR0175 / ISO 15156 for the stated service. It must be ordered and verified — usually by hardness testing reported on the certificate.
What is the difference between MR0175 and MR0103?
MR0175 / ISO 15156 is for oil and gas production; MR0103 / ISO 17945 is for refinery and related sour environments.
Which bolting is used in sour service?
Reduced-hardness grades such as ASTM A193 B7M studs with A194 2HM nuts.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026