Mandrel

A mandrel is a solid rod, bar, or shaft around which other materials are shaped, molded, or otherwise formed. It serves as a core or support during manufacturing processes, ensuring a desired internal shape or dimension. Often made of metal, but can be composed of wood, plastic, or other materials depending on the application. Mandrels can be reusable or expendable and come in various sizes and configurations, from simple cylindrical shapes to complex forms. They are critical in processes like metal spinning, tube bending, wire winding, and the creation of composite structures. The shape and material of the mandrel directly influence the final product's characteristics and quality.

Mandrel meaning with examples

• During metal spinning, a sheet of metal is rotated and pressed against a rotating mandrel. This shaping process allows for the creation of seamless, symmetrical parts, such as cookware or decorative objects. The mandrel defines the internal contours of the finished product, ensuring precise dimensions and a smooth surface.
• In the manufacture of tubing, a mandrel is inserted inside the metal tube to prevent collapse and maintain a constant internal diameter during bending or other forming operations. This ensures that the tube's internal bore remains uniform and does not deform during the shaping process.
• The intricate shapes of fiberglass or carbon fiber composites, like those used in aerospace, are often created by wrapping the fiber around a mandrel. Once the composite material cures, the mandrel can be removed, leaving a hollow structure.
• A watch maker uses a mandrel to support the delicate components when making repairs to watch bracelets or other watch parts. This holds the watch's parts to ensure correct manipulation and assembly for a perfect finish.
• Wire is wound tightly around a mandrel to create coils for electrical components like transformers or electromagnets. The mandrel's size and shape dictates the coil's inductance, impacting the device's electrical properties.