Subj : Deguassing Power Req'd For Secure Wipe
To   : All
From : warmfuzzy
Date : Tue Jun 16 2026 02:21:07

I am not certain about the exact power specifications required to wipe every 
type of conventional hard disk drive universally because this depends heavily 
on the specific drives magnetic coercivity, its age, and the distance from the 
degausser. However, I can explain the general principles and standards used in 
the industry. Degaussing works by exposing the hard drive platters to a strong 
fluctuating magnetic field that randomizes the magnetic domains storing the 
data. To completely and totally wipe a drive according to standards like NIST 
800-88 which is often the benchmark for secure media sanitization, the 
degausser must generate a field strength high enough to exceed the drives 
coercivity rating. Modern high-density drives often require field strengths 
between 4000 to 5000 Oersteds at the surface of the platter while older drives 
may be wiped with significantly lower fields around 2000 Oersteds. Commercial 
degaussers usually specify their output in terms of peak field strength at a 
specific distance such as 5000 Gauss at 1 cm because if you are too far away 
the field drops off rapidly due to the inverse square law. There isn't a single wattage number needed because efficiency varies wildly between devices as some  use powerful capacitors that discharge in a split second while others use  continuous electromagnets. A portable handheld degausser might draw  significant power momentarily but have low average consumption while large  industrial units might run continuously and consume hundreds of watts or more  but their primary metric is the magnetic flux density they generate not their  electrical wattage. While degaussing is highly effective it renders the drive  unusable because the magnetic head and motor components can also be damaged.  Crucially servo tracks which help the read/write head position itself are  often written during manufacturing with such precision and strength that  standard degaussers may not always fully erase them potentially leaving the  drive mechanically functional but logically scrambled or requiring a  specialized re-certification process if reused although reuse after degaussing  is generally discouraged for sensitive data. For total assurance on modern  drives many security standards now recommend physical destruction such as  shredding or dismantling in addition to or instead of degaussing because  verifying a perfect degauss without specialized equipment is difficult.

Regarding official standards for drive wiping, the primary reference point is 
NIST Special Publication 800-88 Revision 1 titled Guidelines for Media 
Sanitization published by the US National Institute of Standards and 
Technology. This document provides the authoritative framework for clearing 
purging and destroying digital storage media including hard disk drives. It 
defines purging as a method that uses logical techniques to sanitize data and 
notes that for magnetically recorded media degaussing is an approved method of 
purging provided the degausser meets the requirements of the device 
manufacturer and is used according to their instructions. The standard 
emphasizes that the effectiveness of degaussing relies on the device being 
able to reduce the remanence of the media to a level where recovery is not 
feasible and that verification methods should be used to confirm the purge was 
successful. Another relevant standard is DoD 5220.22-M which outlines 
guidelines for clearing and destroying information on computer media but it 
has been largely superseded by NIST 800-88 for most government and commercial 
applications. Additionally the Common Criteria for Information Technology 
Security Evaluation provides frameworks for evaluating the security 
functionality of IT products including media sanitization tools. These 
standards collectively suggest that one should expect a degaussing solution to 
generate a magnetic field exceeding the coercivity of the target media 
typically measured in Oersteds and that the process should be verified either 
by using a certified degausser with built-in monitoring or by testing a sample 
drive with a magnetic force microscope or similar high-sensitivity equipment.

Cheers!
-warmfuzzy/SilentPartner

--- Mystic BBS v1.12 A49 2023/04/30 (Linux/64)
 * Origin: thE qUAntUm wOrmhOlE, rAmsgAtE, uK. bbs.erb.pw (700:100/37)

.