Festplattenschredder

When a hard drive can no longer be erased or the data is too sensitive, physical destruction remains. The tool for this is usually a hard drive shredder. Here you will learn how such machines work, what the particle size means and what to look out for during destruction.

How a hard drive shredder works

A hard drive shredder usually has two or more counter-rotating shafts with hardened cutting blades. They pull in the data carrier, tear open the housing and cut up circuit boards, magnetic platters and memory chips. A sieve beneath the cutting unit only lets through particles up to a certain size. Larger pieces pass through the cutting unit again.

The smaller the particles are meant to be, the more complex the process. SSDs, USB sticks and memory cards require particularly small particles, because even a single memory chip can contain a lot of data. Some systems therefore work in several stages: a pre-shredder breaks the material down roughly, a second cutting unit or a Disintegrator shreds it finely.

Particle size and security levels

The DIN 66399 standard defines security levels with a maximum particle area for each material class. Material class H applies to hard drives with magnetic platters:

Security level	Requirement
H-3	Hard drive deformed
H-4	Particles of at most 2,000 mm²
H-5	Particles of at most 320 mm²
H-6	Particles of at most 10 mm²
H-7	Particles of at most 5 mm²

Material class E applies to electronic data carriers such as SSDs, with its own limit values. Which level is appropriate for which data is explained in the entry Security level H-5 and our guide DIN 66399: protection classes and security levels.

Shred, punch or erase?

One hard drive punch only deforms or perforates a hard drive. This renders it unusable but only reaches low security levels, because large parts of the platters remain intact. A shredder reduces it completely.

Both methods destroy the data carrier and therefore its value. A certified erasure preserves the hard drive and enables reuse. Our guide shows when which approach pays off Hard drive destruction: costs and alternatives.

Hard drive shredder at Second IT

Second IT destroys data carriers exclusively in-house, i.e. without transport to external sites. Destruction is mechanical in accordance with DIN 66399, certified for security level H-5, in areas with access control and video surveillance. Each data carrier is registered by serial number beforehand, and a certificate of destruction is issued at the end. The materials are then separated and recycled. More on the in-house data carrier destruction.

Frequently asked questions about the hard drive shredder

Can a hard drive shredder also destroy SSDs?

Yes, if it is designed for the required particle size. Because SSD memory chips are very small, DIN 66399 sets stricter limit values for electronic data carriers than for hard drives with magnetic platters.

Is it enough to drill a hard drive yourself?

Not for sensitive data. Large areas of the platters remain between the drill holes. In addition, there is no proof per serial number, which you need for accountability.

What happens to the particles after shredding?

The particles contain metals such as aluminum and steel as well as circuit board residues. They are separated and sent for recycling so that the raw materials are recovered.

What is the difference between a hard drive shredder and a hard drive punch?

A punch only deforms or perforates the hard drive. This renders it unusable but only reaches low security levels, because large parts of the platters remain intact. A shredder reduces the data carrier completely to particles.

Which security level does a hard drive shredder reach?

That depends on the design. A sieve beneath the cutting unit determines the maximum particle size, and this decides the level under DIN 66399. For hard drives the range extends from H-3 to H-7. H-5 means particles of at most 320 mm².