Degaussing erases a hard drive with a powerful magnetic field. But it only works on magnetic media, it destroys the drive for good, and it does nothing to an SSD. This guide explains how it works, when to use it, and how a business proves it was done.
Degaussing is a method of data destruction that exposes magnetic storage media to a strong magnetic field, permanently erasing the data by scrambling the magnetic pattern that stores it. It works on magnetic media such as hard drives and backup tapes, and it renders the drive permanently unusable. It has no effect on solid-state drives, USB drives or phones, because those store data electronically, not magnetically. For a business, degaussing is one of several secure options, chosen based on the device and whether the hardware needs to be reused.
A hard drive stores data as tiny magnetised regions on its platters. Each region points one way or the other, and that pattern is what encodes your files. Degaussing works by hitting those platters with a magnetic field far stronger than the drive's own, which randomises the magnetic pattern so the original data can no longer be read or reconstructed.
The strength matters. Media resists being demagnetised, and a degausser has to produce a field strong enough to overpower that resistance across the whole drive. A modern hard drive needs a very powerful field to be erased properly, which is why proper degaussing uses purpose-built commercial equipment, not a household magnet.
A strong magnetic field turns ordered, readable data into random noise, and takes the drive with it.
Degaussing also wipes the servo tracks and firmware written at the factory, which the drive needs in order to spin up and find data. That is why a degaussed hard drive is permanently unusable and cannot be reformatted or reused. Degaussing destroys the data and the drive together.
No. Degaussing does nothing to a solid-state drive. SSDs, NVMe drives, USB sticks, SD cards and phones store data in NAND flash memory, which holds information electronically rather than magnetically. A magnetic field has no effect on it, so a degausser leaves the data fully intact. This is the single most common and most dangerous misconception about degaussing.
Because so many business devices now use flash storage, this matters. Running an SSD through a degausser and assuming the data is gone is a data breach waiting to happen. Flash media must be handled a different way: cryptographic or firmware secure erase for a drive you want to reuse, or physical destruction (shredding) for a drive that is retired. A provider that does not check whether a drive is magnetic or flash before choosing a method is a warning sign.
The right method depends on the media and whether the hardware needs to be reused. Here is the simple decision.
| Your situation | Method | Why |
|---|---|---|
| Magnetic hard drive or backup tape, being retired | Degaussing or physical shredding | A magnetic field or a shredder destroys the data; the media is then recycled |
| SSD, NVMe, USB, SD card or phone, being retired | Secure erase or shredding. Never degauss. | Flash is electronic, so a magnet has no effect. Erase to the drive's own standard or shred it |
| Any drive you want to reuse or resell | Certified software wipe (NIST 800-88) | Overwriting erases the data while keeping the hardware fully working |
In practice a business rarely picks one method for everything. A single collection often mixes magnetic drives, solid-state drives and units worth reusing, so each is matched to the right approach. See our hard drive shredding and data wiping services for the other two paths.
The recognised international guideline for media sanitisation is NIST 800-88. It defines three levels of destruction: Clear, Purge and Destroy. Degaussing sits at the Purge level for magnetic media, meaning it is designed to protect against laboratory and forensic recovery.
One current point worth knowing, which most older articles miss: the latest revision of NIST 800-88 places more weight on other sanitisation methods and notes that degaussing can be less effective on the newest, very high-density magnetic drives. The practical takeaway is not that degaussing is obsolete, but that it has to be done with equipment matched to the media and backed by proper process control. A reputable provider confirms the degausser is strong enough for the drives being handled and documents the result.
This is where degaussing is different from a software wipe. When you wipe a drive with software, the tool can read the drive afterwards and verify the erase. A degaussed drive cannot be powered on or read at all, so there is nothing to read back. Assurance therefore comes from process control rather than a post-check.
The degausser's field strength is confirmed to exceed the coercivity of the drives being processed, and the equipment is maintained and checked.
Every drive is recorded by serial number as it is processed, so the job can be reconciled against your asset register.
You receive a certificate documenting what was destroyed, the method, the date and the operator, as your evidence for audit and compliance.
Under Australian Privacy Principle 11.2 of the Privacy Act 1988, a business must take reasonable steps to destroy or de-identify personal information it no longer needs. If an old drive is exposed, it can become a notifiable breach reported to the Office of the Australian Information Commissioner. The certificate is how you show the data was destroyed properly. Serious or repeated breaches can attract penalties of $50M or more, according to the OAIC.
Penalty figure from a named public source; certification and process facts from ITC.
ITC Asset Management provides degaussing as one part of a full data destruction service for Sydney businesses. We assess each device first, so magnetic drives are degaussed or shredded, solid-state media is securely erased or shredded, and drives you want to reuse are sanitised to the NIST 800-88 standard using Blancco software. Nothing is guessed at.
Every device is logged by serial number and moved under secure chain of custody to our North Rocks facility. Each job ends with a Certificate of Data Destruction, and the physical drive is then recycled in line with AS/NZS 5377, with a Certificate of Recycling. The work is backed by four ISO certifications, including ISO/IEC 27001 for information security, and we have served Sydney businesses since 2018.
Explore our degaussing service, our secure data destruction service, and our certifications.
Common questions about degaussing.
No. SSDs, NVMe drives, USB sticks, SD cards and phones store data in NAND flash memory, which is electronic rather than magnetic, so a magnetic field has no effect and the data stays intact. Flash media must be securely erased to the drive's own standard or physically shredded, never degaussed.
No. Degaussing wipes the servo tracks and firmware the drive needs to operate, along with your data, so the drive is permanently dead and cannot be reformatted or reused. If you want to keep hardware working, use a certified software wipe instead.
For magnetic hard drives and backup tapes, degaussing is a recognised destruction method that sits at the Purge level under NIST 800-88. What makes it compliant in practice is doing it with equipment matched to the media and documenting it with a Certificate of Data Destruction, which is your evidence under Australian Privacy Principle 11.2 of the Privacy Act 1988. It does not apply to flash media.
Degaussing uses a magnetic field to erase magnetic drives and destroys the drive in the process. Shredding physically destroys any drive, magnetic or flash. Software wiping overwrites the data while keeping the drive usable, so it suits equipment you want to reuse or resell. The right choice depends on the media type and whether the hardware is being kept.
A degaussed drive cannot be powered on or read, so it cannot be checked afterwards like a software wipe can. Assurance comes from process control: a degausser confirmed strong enough for the drives, each unit logged by serial number, and a Certificate of Data Destruction issued for the job. Ask your provider for all three.
ITC matches every device to the correct method, degaussing, shredding or a certified wipe, across Sydney and NSW, with a Certificate of Data Destruction for every job.
