API 2W is the API’s spec “Steel Plates for Offshore Structures”.

Grade 50  (the strength is 344 MPa. )

The plates are designed for use in critical potions of offshore structures which have to resist impact, plastic fatigue loading and lamellar tearing.  API 2W grade 50 steel is at least equivalent in minimum performance to API spec 2H steel grades. The higher performance of API 2W50 is then delivered through the impact of the TMCP rolling.

The main use for API 2W Grade 50 plates is in tubular joints, stiffened plate construction and other locations where parts of the plates will be subject to tension in the through thickness or Z direction (which is why so many of out plates are sold with Z35 testing.).