1045 steel is a commonly used carbon steel alloy that can be suitable for certain types of swords, depending on the specific design, intended use, and personal preferences. Here are some considerations regarding the use of 1045 steel for a sword:

1. Moderate Hardness and Toughness: 1045 steel has a moderate carbon content, typically around 0.45% to 0.55%. This results in a hardness of approximately 45 to 50 HRC (Rockwell Hardness Scale) when properly heat treated. While 1045 steel is not as hard as higher carbon steels used for swords, it can still provide a good balance of hardness and toughness. This allows for a blade that can withstand impact and bending without fracturing or chipping excessively.
2. Affordability and Availability: 1045 steel is relatively affordable and readily available, making it a popular choice for entry-level or cost-effective swords. It is commonly used for functional and decorative swords intended for display, light cutting practice, or stage performances.
3. Machinability: 1045 steel is known for its good machinability, which allows for easier shaping, grinding, and finishing processes during sword production. This can be advantageous for swordsmiths or manufacturers.
4. Limitations for Heavy Use: While 1045 steel can provide satisfactory performance for light cutting or decorative purposes, it may not be as suitable for intensive cutting practices or heavy combat scenarios. The moderate hardness and toughness of 1045 steel may not be sufficient for prolonged and demanding use.

It's important to note that the suitability of 1045 steel for a sword depends on various factors, including the specific design, heat treatment, and intended use. If you are considering a sword made from 1045 steel, it is recommended to consult with experienced swordsmiths or experts who can provide guidance based on your specific requirements and preferences to ensure the suitability and performance of the blade.