The type of metal product to be used on a job is usually designed in which document?

The correct answer is project specifications. This document is critical in outlining the specific requirements for the materials and products to be used in a construction project, including the type of metal products. Project specifications provide detailed information about the materials' properties, standards, and performance criteria necessary for the project.

Construction drawings primarily illustrate how the project should be built, including layout and dimensions, but they do not typically specify the types of materials to be used. Project proposals provide a summary of the project scope and may include budget estimates but lack the detailed material specifications found in the project specifications. Material safety data sheets focus on the safety and handling of materials rather than their specific application or type in a construction context. Therefore, project specifications serve as the authoritative document for determining which metal products should be utilized in the job.