Nifty Alloys LLC - Special Steel Supplier & stockist

What Is NACE MR0175 / ISO 15156? NACE MR0175 / ISO 15156 is the internationally recognised standard for selecting metallic materials in oil and gas environments containing hydrogen sulphide (H₂S). It defines which alloys and grades are acceptable to prevent sulfide stress cracking (SSC), hydrogen induced cracking (HIC), and related failure mechanisms. The standard is structured in three parts: ISO 15156-1 — General principles for selecting cracking-resistant materials. ISO 15156-2 — Requirements for carbon and low-alloy steels. ISO 15156-3 — Requirements for corrosion-resistant alloys (CRAs): stainless steels, duplex SS, and nickel alloys. Most purchase orders reference both designations — e.g. NACE MR0175 / ISO 15156 Part 3 — to avoid ambiguity. Major operators and EPC contractors worldwide mandate compliance for all sour service equipment. Sour Service vs Sweet Service Sweet service contains no H₂S above threshold levels. Standard materials like ASTM A105 or A106 are acc...

When you raise a purchase order for nickel alloys, duplex stainless steel, titanium, or any engineered alloy in a project environment, the certificate type you specify on that PO determines who tests the material, which batch is tested, and whether an independent party validates the results before shipment. Getting this wrong — or leaving it unspecified — creates downstream QA problems, rejected material at incoming inspection, and potential project delays. Every certified metallic product ships with a mill certificate (MTC) — but not all certificates carry the same weight. EN 10204 is the internationally recognised standard that defines exactly what each document type must contain and who must sign it. This guide focuses on the three certificate types most relevant to industrial procurement — Types 2.2, 3.1, and 3.2 — and explains when to specify each. What Is EN 10204? EN 10204 — formally titled Metallic Products: Types of Inspection Documents — is a European standard originally d...