G40.21-98

1. Scope 1.1 This Standard covers structural quality steel plates, shapes, hollow sections, sheet piling, and bars for general construction and engineering purposes. 1.2 A number of strength levels are available under this Standard and are designated by the minimum yield strength in megapascals (ksi). The common grades, types, and strength levels are shown in Table 1. Charpy V-Notch categories are as shown in Tables 9A and 9B. The purchaser shall specify the grade and, if applicable, the category. 1.3 The following types of steel are covered by this Standard: (a) Type W - Weldable Steel. Steels of this type meet specified strength requirements and are suitable for general welded construction where notch toughness at low temperatures is not a design requirement. Applications include buildings, compression members of bridges, etc. (b) Type WT - Weldable Notch-Tough Steel. Steels of this type meet specified strength and Charpy V-Notch impact requirements and are suitable for welded construction where notch toughness at low temperature is a design requirement. The purchaser, in addition to specifying the grade, must specify the required category of steel that establishes the Charpy V-Notch test temperature and energy level. Applications include primary tension members in bridges and similar elements. (c) Type R - Atmospheric Corrosion-Resistant Steel. Steels of this type meet specified strength requirements. The atmospheric corrosion resistance of these steels in most environments are substantially better than that of carbon structural steels with or without a copper addition.* These steels are welded readily up to the maximum thickness covered by this Standard. Applications include unpainted siding, unpainted light structural members, etc, where notch toughness at low temperature is not a design requirement. (d) Type A - Atmospheric Corrosion-Resistant Weldable Steel. Steels of this type meet specified strength requirements. The atmospheric corrosion resistance of these steels in most environments are substantially better than that of carbon structural steels with or without a copper addition.* These steels are suitable for welded construction where notch toughness at low temperature is not a design requirement. Applications include those similar to Type W. (e) Type AT - Atmospheric Corrosion-Resistant Weldable Notch-Tough Steel. Steels of this type meet specified strength and Charpy V-Notch impact requirements. The atmospheric corrosion resistance of these steels in most environments are substantially better than that of carbon structural steels with or without a copper addition.* These steels are suitable for welded construction where notch toughness at low temperature is a design requirement. The purchaser, in addition to specifying the grade, must specify the required category of steel that establishes the Charpy V-Notch test temperature and energy level. Applications include primary tension members in bridges and similar elements. (f) Type Q - Quenched and Tempered Low Alloy Steel Plate. Steels of this type meet specified strength requirements. While these steels shall be weldable, the welding and fabrication techniques are of fundamental importance and must not adversely affect the properties of the plate, especially the heat-affected zone. Applications include bridges and similar structures. (g) Type QT - Quenched and Tempered Low Alloy Notch-Tough Steel Plate. Steels of this type meet specified strength and Charpy V-Notch impact requirements. They provide good resistance to brittle fracture and shall be suitable for structures where notch toughness at low temperature is a design requirement. The purchaser, in addition to specifying the grade, must specify the required category of steel that establishes the Charpy V-Notch test temperature and energy level. While these steels shall be weldable, the welding and fabrication techniques are of fundamental importance and must not adversely affect the properties of the plate, especially the heat-affected zone. Applications include primary t