1045 steel is considered a medium-carbon steel rather than a high-carbon steel. It contains approximately 0.45% carbon content, which places it in the medium range of carbon content for steel grades.

High-carbon steels typically have a carbon content above 0.60%. While 1045 steel has a relatively higher carbon content compared to low-carbon steels, it is not categorized as a high-carbon steel. Instead, it falls within the medium-carbon range.

1045 steel is commonly used in various applications that require a balance of strength, toughness, and machinability. It offers good strength and hardness when properly heat-treated, along with reasonable wear resistance. It is often used for components such as gears, shafts, axles, bolts, and studs.

It's worth noting that the categorization of steel as low-carbon, medium-carbon, or high-carbon can sometimes vary depending on different sources or standards. The carbon content ranges used for classification can differ. However, based on common standards and general classifications, 1045 steel is considered a medium-carbon steel.