T10 steel can be used for sword blades, including Japanese-style swords, with satisfactory results. While T10 steel is not a traditional material for crafting katana blades, it is a popular choice for some modern swordsmiths who seek its specific properties and characteristics.

Here are some factors to consider regarding T10 steel for sword blades:

1. Hardness and Edge Retention: T10 steel has a high carbon content, typically around 1.0% to 1.1%, which contributes to its hardness. When properly heat treated, T10 steel can achieve a high level of hardness, allowing for excellent edge retention. This can result in a sword blade that maintains a sharp edge for extended periods of use.
2. Toughness: T10 steel generally exhibits good toughness, which is crucial for a sword blade to withstand impacts and bending without fracturing or chipping. A tough blade is less likely to break during combat or training.
3. Machinability: T10 steel is known to have good machinability, meaning it can be shaped and worked on relatively easily during the manufacturing process. This allows for effective forging and grinding to create the desired shape and profile for the sword blade.
4. Heat Treatment and Craftsmanship: The quality of the heat treatment process and the craftsmanship involved in forging and shaping the sword blade are critical factors that significantly influence the performance and durability of T10 steel. Skillful heat treatment is essential to optimize the steel's properties and ensure a well-balanced sword blade.

While T10 steel can provide desirable characteristics for sword blades, it's important to note that the selection of a steel type depends on various factors, including the intended use of the sword, the desired performance characteristics, and personal preferences. If you are considering a sword made from T10 steel, it is recommended to consult with experienced swordsmiths or experts who can provide insight into the specific design, heat treatment, and quality of the blade to ensure its suitability for your intended purpose.