Tsuba, the handguards found on katana and other Japanese swords, are traditionally made from a variety of materials. The specific material used for tsuba can vary depending on the era, region, and the preferences of the swordsmith or owner. Here are some common materials used for making tsuba:

1. Iron: Iron is a commonly used material for tsuba. It is durable and provides protection for the hands during combat. Iron tsuba can be plain or intricately decorated with engravings, inlays, or other artistic elements.
2. Copper and Brass: Copper and brass are also utilized in tsuba production. These metals can be used alone or in combination with other materials, such as iron or gold. Copper and brass tsuba are known for their beautiful patinas and can be intricately carved or decorated.
3. Silver and Gold: Some tsuba feature silver or gold inlays, overlays, or decorations. These precious metals are used to add a touch of luxury and enhance the aesthetic appeal of the tsuba.
4. Other Materials: In addition to metals, tsuba can be crafted from materials such as wood, bamboo, horn, or even materials like shakudo (a copper-gold alloy) or shibuichi (a silver-copper alloy) for specific artistic effects.

The choice of material for tsuba often reflects the craftsmanship, artistic style, and personal preferences of the swordsmith or owner. Tsuba designs can range from simple and functional to highly intricate and ornate, with various materials chosen to achieve the desired aesthetic and functional qualities.