1. has different functions: round parts of dies are usually used for the manufacture of dies and fixtures, mainly for the positioning, supporting and fixing of die parts, while pins are mainly used for the connection, positioning and transmission of power parts.

2. Different structures: the shape and size of the round part of the mold are different, which can be round, square, rectangular or other shapes, generally with bosses, grooves, holes and other structures, while the pins are generally cylindrical or conical, with characteristics such as diameter, length and angle.

3. Different materials: Generally, the round parts of the mold need to have certain hardness, toughness and wear resistance, and tools steel, tungsten steel, alloy steel and other materials are usually used, while pins are usually made of stainless steel, carbon steel, brass and other materials.

4. Different uses: the round parts of molds are mainly used for the manufacture of molds and fixtures, which requires high machining accuracy and positioning accuracy of workpieces, while the pins are mainly used in mechanical transmission systems, electronic components and other fields, which requires high connection and positioning accuracy.