This specification applies to the welding of all principal structural weldments and all primary welds used in the manufacture of cranes for industrial, mill, power house, and nuclear facilities. It also applies to other overhead material handling machinery and equipment that support and transport loads within the design rating, vertically or horizontally, during normal operations. It also applies, when agreed upon between the buyer and manufacturer, to loading caused by abnormal operations or environmental events, such as seismics. Secondary welds that will be subjected to stresses of less than 6000 psi (41.4 MPa)' need only meet the requirements of Section 5, Workmanship, and Section 8, Weld Quality and Inspection. The engineering drawings shall specify the joint detail, type, and size of weld. This specification is not intended for application to construction- or crawler-type cranes.

All provisions of this specification are equally applicable to the strengthening and repairing of existing overhead cranes and material handling equipment as described above.