SM125S is a low alloy High Strength Carbon steel OCTG material suitable for medium Sour Service severity applications. SM125S is a Sulfide Stress Cracking (SSC) resistant material.

SSC failure mechanism is a form of Hydrogen embrittlement in combined presence of H2S, water and tensile stresses. Using cutting edge R&D technology, SM125S was the first 125 ksi Sour Service material released in 2003. SM125S benefits from SMI's unrivaled know-how in manufacturing sour service materials since the 70's and best-in-class quality control.

SM125S has no equivalent in API 5CT/ISO 11960 grades and in order to achieve its superior Sour Service properties SMI applies a very strict QA/QC throughout its manufacturing route from Steel Making to Heat Treatment processes.