How to demagnetize a steel shaft

[mike gibson]

How can I demagnetize a steel shaft. Heat is not an option. The shaft is 0.6 inches diameter and 3 feet long.

Note I have seen several devices for sale that seem extremely expensive. Perhaps, if I know what the actual physical process is, then I can just build a device to demagnetize the steel.

Also, I have a magnetometer to measure the after affects of the demagnetization process.

Thanks in advance for any input.

 

[FredGarvin]

http://klabs.org/DEI/References/design_guidelines/design_series/1220.pdf

 

[astrokreng]

I would recommend using an alternating current (AC) demagnetizer to demagnetize the steel shaft. This process involves passing an AC current through the shaft, which will disrupt the alignment of the magnetic domains within the steel and demagnetize it. This method is commonly used in industrial applications and is relatively simple to implement, especially for a shaft of this size.

To build your own demagnetizing device, you will need a power supply capable of producing an AC current, as well as a coil of wire to create a magnetic field around the shaft. The coil should be wrapped around the shaft and connected to the power supply. The frequency and strength of the AC current will depend on the type of steel used in the shaft. It is important to note that the process may need to be repeated multiple times to fully demagnetize the shaft.

I would also recommend using your magnetometer to measure the magnetic field before and after the demagnetization process to ensure the desired level of demagnetization has been achieved. It is important to follow all safety precautions when working with electricity and magnetic fields.

In conclusion, using an AC demagnetizer is a cost-effective and efficient method for demagnetizing a steel shaft without the use of heat. With proper precautions and equipment, it is possible to build your own demagnetizing device and achieve the desired results.