Hard drive shredding is the physical destruction of hard drives. A hard drive shredder mangles the hard drives in such a manner that thieves will be less inclined to attempt to retrieve the data contained on the shredded remnants. The common misconception is that shredding media renders the data impervious to recovery. However, it is well recognized that shredding or physically destroying the media does not remove the data from the hard drive disk platters. Because the data remains on a shredded hard drive, the National Security Administration (NSA) requires all media to be purged or degaussed before the media is released for shredding or destruction.
Degaussing is the process of exposing the medial to a strong magnetic field to eliminate all data from working and non-working hard drives and tape. Hard drives are rendered unusable after being degaussed.
The NSA requires hard drives to be shred to 2 mm particles. Shredding to 2×2 mm particles has limitations as the equipment necessary to shred an HDD is at minimum the size of a cement truck and it must have a negative pressure vacuum system to contain the dust particles which at this size are toxic. An HDD is made of several materials including steel, aluminum, various plastics, gold, copper, etc. Dust-sized particles would extremely hazardous to breathe. Shredding requires utilizing a third-party vendor to transport the media from its secure location to the site of the shredding equipment. To eliminate the chances of a data breach during transport, the NSA requires all media to first be degaussed before leaving its secure facility and being handed over to a third party shredding vendor.