How to Make Solenoid Magnets

John Gugie

A solenoid is basically a three-dimensional tight coil of wire. However, when a solenoid is connected to an electric current, it creates an electromagnetic field within the inside of the coil of wire. Solenoids can create controlled magnetic fields and as electromagnets.

More specifically, solenoids refer to magnets designed to create uniform magnetic fields for scientific experiments. There are many types of solenoids with many different uses. Some types include the following solenoids. Rotary voice coils are used in devices such as disk drives; electromechanical solenoids in electronic paintball markers, pinball machines, dot matrix printers and fuel injectors; pneumatic solenoid valves in pistons or actuators; pneumatic solenoids in electronic controllers and pneumatic systems; hydraulic solenoid valves in irrigation systems; transmission solenoids in automatic transmissions; starter solenoids are used in automobile ignitions; and many other types of solenoids in countless devices. The solenoid was invented in the early 19th century by the French physicist, André-Marie Ampère, who is best known for his research of the magnetic fields produced by wires carrying electric current. His work began where the Danish physicist, Hans Oersted, left off. In 1819, Oersted had discovered that compass needles are deflected by wires carrying electric current.


  1. Find an empty, hollow cardboard roll, such as a toilet roll or a narrower tube.

  2. Take a long length of insulated copper wire and wrap it around and around the tube tightly. Aim for at least a 100-200 turns; double-layered, if possible.

  3. Strip the insulation off of both ends of the wires; about 1 centimeter in length.

  4. Connect each end of the wire to a battery to one wire,

  5. Put a long, thin, steel object, such as a sewing needle, in the tube and it should move due to the electromagnetic field created by the solenoid and electric current.


The wire and battery can get very hot and drain the battery if connected for too long, so either connect it for a few seconds at a time or connect a resistor between one end of the wire and the battery. The resistor will prevent too much current from overheating the wire. Use the proper strength resistor for the voltage of the battery being used.