Degaussing is one of the oldest methods of destroying data on a storage device, and one of the most misunderstood. It still works exactly as well as it always did on the media it was designed for. It does nothing at all on the media most organizations are retiring today.
This guide explains what degaussing does, which drives it works on, where it fails, and how to tell which category your equipment falls into.
Looking for the service rather than the explainer? See hard drive and media shredding for physical destruction of HDDs, SSDs, and tape, or on-site hard drive shredding if you need to witness the destruction at your own facility.
What Degaussing Actually Does
A degausser is a machine that generates a strong magnetic field. Traditional storage media hold data as patterns of magnetic charge on a coated disc or film. Passing that media through a powerful enough field scrambles those patterns beyond reconstruction.
It is fast, it leaves no readable data behind, and it does not require opening the device. For the right media, it is a legitimate and well-established destruction method.
What Degaussing Works On
Degaussing is effective on magnetic media, which includes:
- Traditional spinning hard disk drives (HDDs)
- LTO, DLT, and other backup tape formats
- Cassettes, reels, and cartridge tape
- Floppy disks and other legacy magnetic formats
If your organization is retiring a tape library or a rack of older spinning drives, degaussing remains a valid option. It has not been superseded for that media.
Degaussed tape still has to leave the building, though, and a degausser does nothing for the rest of a mixed retirement. We shred DLT tape, VHS, CDs and floppy disks alongside hard drives and SSDs, so a tape library and the servers it backed up can go out on the same job. See hard drive and media shredding for the full list of media we handle.
Where Degaussing Fails: SSDs and Flash Storage
Solid state drives do not store data magnetically. They hold it as electrical charge in flash memory cells. A magnetic field, however strong, does not disturb those cells.
Run an SSD through a degausser and the data is still there, fully intact and fully recoverable. As TechRepublic has noted, the traditional methods of destroying a hard drive are not effective against an SSD, with the exception of physically destroying the device.
This is the part that catches organizations out. SSDs are now standard in laptops and increasingly common in servers and workstations. A disposal process built around degaussing ten years ago may be quietly failing on a large share of today's equipment. The same applies to the flash storage soldered directly onto the logic board in many tablets, phones, and newer laptops, where there is no removable drive to degauss in the first place.
Can a Degaussed Drive Be Reused?
No. On a hard disk drive, the magnetic field does not only erase your data. It also wipes the servo tracks written at the factory, which are what allow the drive heads to find their position. Without them the drive cannot be initialized or reformatted.
That matters commercially. A degaussed drive has no resale value and cannot be redeployed internally. If some of the equipment you are retiring still has useful life, degaussing removes that option permanently. Secure erasure may be the better choice for drives you intend to reuse or resell.
It is worth doing the arithmetic before you degauss. Every laptop, desktop and server you recycle with us earns a $10 credit toward your costs, and working machines may qualify for direct payment through our buy-back program. A degausser turns equipment that could have paid for its own disposal into scrap metal.
What NIST 800-88 Says About Degaussing
The NIST SP 800-88 guidelines for media sanitization recognize degaussing as a valid technique for magnetic media, and explicitly do not recognize it for flash-based storage. The standard's guidance follows the physics: match the method to the media.
For a compliance program, that distinction matters more than the method itself. An auditor will want to see that your process identifies the media type and applies an appropriate technique, and that you hold documentation proving it.
Degaussing, Secure Erase and Shredding Compared
Three methods, and none of them covers everything. This is the short version of which to reach for:
| Method | Magnetic HDD | SSD and flash | Backup tape | Reusable after | Something to look at |
|---|---|---|---|---|---|
| Degaussing | Works | No effect | Works | No | No |
| Secure erase / overwrite | Works | Works, with vendor support | Limited | Yes | No |
| Shredding | Works | Works | Works | No | Yes |
The last column matters more than people expect. Degaussing and overwriting both leave you holding a device that looks exactly as it did before, so the evidence is entirely paperwork. Shredding produces a bin of fragments an auditor can see.
The Practical Drawbacks
Even where degaussing works, it carries trade-offs worth knowing:
- No visual confirmation. A degaussed drive looks identical to a working one. Verification depends entirely on process and paperwork rather than on anything you can see.
- Field strength has to match the media. Degaussers are rated in Oersteds, and the rating has to exceed the coercivity of the media going through it. Modern high-coercivity drives need a stronger field than older ones, so a degausser bought for a previous generation of hardware can leave recoverable data behind.
- It destroys resale value. As above, the drive is finished afterward.
- It does not cover mixed loads. Most retirements today contain a mix of HDDs, SSDs, and devices with onboard storage. One method will not handle all of it.
When Physical Destruction Makes More Sense
Shredding works on every media type, magnetic and flash alike, and it produces something you can actually look at. For organizations that need to demonstrate destruction to an auditor, a bin of shredded drive fragments is easier to evidence than a certificate stating a magnetic field was applied.
It is usually the more practical answer for a mixed load, which most retirements now are.
How We Handle Data Destruction
At Data Recycling of New England, our process starts by overwriting the drive, replacing existing data with meaningless binary. For equipment that is being retired outright, we also offer physical destruction by shredding, which is the most secure route available and works regardless of whether the media is magnetic or flash. Hard drives go through an SSI dual-shaft shredder rated at over 2,000 drives an hour. SSDs and small media go through an Intimus FlashEx, which reduces them to particles of roughly 0.16 by 0.6 inches.
Remaining metal is recycled rather than landfilled, and we provide a Certificate of Data Destruction for your records. Our process follows NIST SP 800-88, applying the appropriate technique for each media type rather than a single method across the board.
Degaussing FAQ
Does degaussing work on SSDs?
No. Solid state drives hold data as electrical charge in flash memory cells, not as magnetic patterns, so a magnetic field has nothing to act on. The data survives intact. The same is true of the onboard storage in tablets, phones and newer MacBooks.
Can a hard drive be reused after degaussing?
No. The field wipes the servo tracks written at the factory, which the drive heads rely on to find their position. Without them the drive cannot be initialised or reformatted. If you want to reuse or resell the equipment, overwrite it instead.
Is degaussing NIST 800-88 compliant?
For magnetic media, yes. NIST SP 800-88 recognises degaussing as a valid purge technique for magnetic storage, and does not recognise it for flash-based storage. The standard follows the physics.
What about backup tape?
Degaussing works on LTO, DLT and other tape formats. We also shred DLT tape, VHS, CDs and floppy disks, which means a tape library and the hard drives from the same retirement can be handled on one job. See hard drive and media shredding.
How do I prove destruction to an auditor?
You need documentation that identifies the media and the method. We issue a Certificate of Destruction listing captured serial numbers, and on on-site shredding jobs it is printed at your facility before the truck leaves.
If you are not sure which method fits your equipment, get in touch and we will help you work it out.