• Coils are widely used in electrical engineering applications. Wires made of conducting materials are used to make electromagnetic coils. They are used in the manufacture of transformers, motors, chokes and inductors which are used extensively in water heaters, air conditioners, refrigerators and many other electrical appliances. Winding the coil uniformly and tightly is a task which requires skill.
  
  

Hand Winding

• For hand winding a coil, a mandrel and handle are necessary tools. The mandrel is a wooden or metal rod. The diameter of the mandrel should be the same as the inner diameter of the coil. A hole which allows the wire to be wound to pass through it must be drilled across the mandrel. The handle should be attached to one end of the mandrel. The handle is turned to wind the coil around the mandrel. Supports which allow the mandrel to spin can be attached at its ends for easy operation. Hands should be protected with rubber gloves when hand winding coils.
  
  

Drill Winding

• A wooden or metal mandrel may be used, but metal rods are better suited for this method. The cross-drilled hole in the mandrel should remain outside when the mandrel is inserted into the drill. The drill rotates the mandrel and winds the coil.
  
  

Jig Winding

• A winding jig is a single unit which can be used for coil winding. The designs may vary. The mandrel, supports for both ends of the mandrel and a drill will be parts of the jig. A hand- or foot-operated crank or pump may be used to control the speed. This makes the coil winding operation easier, as both hands will be free to guide the wire.
  
  

Industrial Coil Winding

• Mechanized coil winders are used in industry. These coil winding machines may wind single or multiple coils. They may be integrated into the production line or may operate independently. Industrial coil winding machines produce more evenly wound coils. Hand-guided machines, continuous winders and armature winders are used. Devices for adjusting the tension are used to regulate the tension evenly.