Spotted this U-shaped tool with multiple metal blades in my grandmother’s baking bin. It has a wooden handle but looks like some kind of strange knuckles.

4. Why The Handle Is Wood And The Blades Are Metal
The choice of materials in a pastry blender is both practical and traditional. Wood is a preferred material for the handle due to its durability and comfort. It is less likely to cause fatigue during use, as it doesn’t conduct heat or cold, making it pleasant to hold for extended periods.
The metal blades, typically made of stainless steel, are chosen for their strength and resistance to rust. Stainless steel maintains a sharp edge, even though the blades aren’t sharpened like a knife. This ensures the tool can consistently cut through cold, hard butter without bending or breaking.