Hello everyone, I am writing with a strange problem. I have been attempting to make an electromagnetic coil that will have enough power to pick up say an average 9v battery in weight, the small kind found in the back of telly remotes and smoke alarms. I am using iron bolts 5cm long by 0.5cm diameter, and winding these with 0.4mm Enameled copper wire, it is rated 26BS and 25G if that helps any???. I made a small coil to test this and ran it from a 9v battery (not sure of the amps) but it did nothing! I started by leaving about 2cm of unwound straight wire at each end and wound from about 0.5cm down from the head of the bolt and wound it in a clockwise direction for about 2cm down the bolt. This did absolutely nothing still. Is my problem that I need more turns on my coil before I will see the effect. Also, will 9v be enough to lift a small 9v battery in weight, or will I need a larger voltage input. Looking at my bolt I would estimate that in a single layer I could get maybe another half of the original windings on before needing to start a new layer. Also the approx winds without actually counting would be around 35 winds at present. Also I have not insulated the bolt from the winds, should I wrap the bolt in paper first and then begin winding onto the paper (and in saying this if I use rubber tube to insulate the nail, would 2mm thick tube be too thick or would that be trial and error? Lastly, can anyone give me any idea of a good source of information for optimising electromagnets, so I can make the best possible magnet from the start. Thanks in advance for any help!