Carbon steel plates are widely used across engineering structures, machinery manufacturing, shipbuilding, pressure vessels, bridges, and construction. Because multiple global standard systems exist—such as ASTM (U.S.), EN (Europe), JIS (Japan), GB/T (China), and ISO—understanding what specifications apply to carbon steel plates, their key features, and application scopes is essential for material selection, procurement, and design. This article provides a systematic overview of major international standards related to carbon steel plates, compares their similarities and differences, and offers practical guidance on choosing the most suitable specification.