DH36 steel

DH36 is a higher-strength hull structural steel with a minimum yield of 355 MPa, tensile range 490 to 620 MPa, and a Charpy V-notch impact test at minus 20 C, the D toughness grade in the IACS UR W11 / classification-society system. The H36 strength level (AH36, DH36, EH36, FH36) is the workhorse plate for container ships, bulk carriers, and tankers, used where normal-strength grade A steel (235 MPa yield) would need excessive thickness. The letter sets the impact-test temperature: A at 0 C, D at minus 20 C, E at minus 40 C, F at minus 60 C for ice and polar service. The number 36 denotes the 355 MPa minimum yield.