What is inside a hard disk drive?
A hard disk drive stores data on spinning platters, read by heads on an arm that a copper coil swings between two strong magnets. Those magnets are commonly neodymium, which makes a drive a likely place to find rare earths, and its cast body adds a good share of aluminum. Because a drive holds data, the data is dealt with before the materials.1
Materials in a hard disk drive
| Material | Where it sits |
|---|---|
| AluminumMost of its weight | Cast bodies and the platters |
| Steel | Covers, magnet yokes and screws |
| Copper | Voice coils and spindle windings |
| Rare earths | Pair of magnets beside each arm |
| Material | Where it sits |
|---|---|
| Tin | Solder on each board |
| Lead | Solder on the oldest boards |
| Silicon | Controller chips on each board |
| Gold | Connector and chip contacts |
| Silver | Solder and board finishes |
| Palladium | Ceramic capacitors on each board |
| Platinum | Magnetic coating on the platters |
What a hard disk drive of this kind most likely holds. Amounts are given in words, not weights, because content depends on the design.
How a hard disk drive is recycled
The first step is the data: a drive is erased, or physically destroyed, in the way its owner requires before any material is recovered.2 How that is done decides what can be recovered afterward. A drive that is dismantled gives up its two magnets on their steel yokes; a drive that is shredded whole needs a further separation step to pick the magnet material out of the mix.3 From separated magnets, the rare earths can be recovered as elements by solution, furnace or electrochemical routes, or the alloy can be reprocessed into new magnets.34 The cast aluminum body is sorted from other shredded material by eddy-current separators and the steel cover and yokes by magnets, and both metals are remelted.56 The controller board goes with other circuit boards to a copper smelter for its gold, silver and palladium. The magnetic coating of the platters typically holds a trace of platinum, a recognized use of that metal, but it is spread very thin.78
More on each stream: magnet rare earths, steel and aluminum, precious metals.
Find it in the games and recycle it
- Mine the houseExternal hard drive (home office) and Box of old hard drives (attic)
- Mine the warehouseCart of hard drives (data-center bay)
- Sort the device wallHard disk drives (data center and it) and Portable drive (data center and it)
- Find a recycling program near youCheck what the program accepts before you go.
Sources
- Rare earth elements, end use and recyclabilityUSGS
- Electronics Donation and RecyclingUS EPA, Before Donating or Recycling Your Used Electronics; Where to Donate or Recycle
- Rare Earth Permanent Magnets: Supply Chain Deep Dive AssessmentUS Department of Energy
- World-leading rare earth magnet recycling facility launches in West MidlandsUniversity of Birmingham, Innovative rare earth recycling process; About the process, January 15, 2026
- Metal Recycling: Opportunities, Limits, InfrastructureUnited Nations Environment Programme, International Resource Panel (2013)
- Recycling is the primary energy efficiency technology for aluminum and steel manufacturingU.S. Energy Information Administration, Today in Energy (May 9, 2014), Article body, sections on steel (electric arc furnaces) and aluminum (secondary production)
- Metal Recycling: Opportunities, Limits, InfrastructureUnited Nations Environment Programme, International Resource Panel (2013), Section 3.4.1.4 'Copper and nickel scrap smelting as part of a primary copper smelter' and Figure 42 (printed pages 112 to 113)
- Mineral Commodity Summaries 2026: Platinum-Group MetalsUS Geological Survey (February 2026), Page 1, 'Domestic Production and Use' and 'Recycling' paragraphs
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