Difference between ABS DH40 and CCS DH40

ABS DH40 and CCS DH40 are both high-strength shipbuilding steel plates specifically designed for hull construction and marine structures operating in cold environments. They are certified by two major classification societies-ABS (American Bureau of Shipping) and CCS (China Classification Society)-but are technically equivalent in terms of mechanical properties and chemical composition.

ABS Grade DH40 is certified by the American Bureau of Shipping. The designation "DH40" indicates it is a high-strength steel with a minimum yield strength of 390 MPa and a tensile strength range of 510-660 MPa . The "D" signifies the impact test temperature of -20°C, requiring minimum Charpy V-Notch impact energy of 41J (longitudinal) or 27J (transverse) for thicknesses up to 50mm . Typical applications include ship hulls, offshore drilling platforms, container ships, bulk carriers, and critical marine structures.

CCS Grade DH40 is certified by the China Classification Society and serves as the direct equivalent to ABS DH40 in the Chinese classification system . It shares identical mechanical property requirements: minimum yield strength of 390 MPa, tensile strength of 510-660 MPa, and minimum elongation of 20% . Like its ABS counterpart, CCS DH40 requires impact testing at -20°C with minimum 41J (longitudinal) . The chemical composition is comparable, with maximum carbon of 0.18%, manganese of 0.90-1.60%, and microalloying elements such as Nb and V for grain refinement.

Key Differences:
The primary distinction between these two grades lies in their certifying authority and the corresponding quality control system. ABS DH40 complies with American Bureau of Shipping rules and is recognized internationally, particularly in projects requiring ABS certification for vessels destined for ABS-classed fleets. CCS DH40 complies with China Classification Society rules and is typically specified for vessels built in Chinese shipyards or for projects under Chinese classification. From a technical perspective, these steels are considered interchangeable, and major manufacturers can produce plates certified by both societies simultaneously . The choice between them is typically determined by the flag state of the vessel, shipyard preferences, or specific project requirements. Both grades must be supplied with mill test certificates (MTC) bearing classification society surveyor signatures.

Chemical Composition

CCS DH40 high Strength Chemical Composition

Mechanical Property

CCS DH40 high strength property