This book examines the properties of plain carbon steels and enduro metal at elevated temperatures through short-time tensile and expansion tests. It begins by highlighting the necessity for information in this field and critiques current research methods, emphasizing the need for more refined testing techniques. It discusses the relative merits of different steel classes based on proportional-limit findings and recommends the most suitable steels for high-temperature applications. The paper underscores the importance of developing metals and alloys that are workable, machinable, and cost-effective for industrial use at high temperatures, noting the ongoing demand in central stations, oil refineries, and other sectors. It acknowledges the contributions of the American Society for Testing Materials and The American Society of Mechanical Engineers in sponsoring relevant investigations and emphasizes the need for standardized testing methods to ensure reliability in determining the properties of metals at elevated temperatures.