Requirements concerningMATERIALS AND WELDING INTERNATIONAL ASSOCIATION OF CLASSIFICATION SOCIETIES W1 Materials and welding for gas tankers Rev.2 May 2004W2 Test specimens and mechanical testing procedures formaterials Rev.2 July 2003W3 DeletedW4 DeletedW5 DeletedW6 DeletedW7 Hull and machinery steel forgings Rev.3 May 2004W8 Hull and machinery steel castings Rev.2 May 2004W9 Grey iron castings Rev.2 May 2004W10 Spheroidal or nodular graphite iron castings Rev.2 May 2004W11 Normal and ...