Hard Drive Shucking Guide for NAS

Quick Recommendation

Buy a WD Elements 18TB or WD easystore 18TB external drive when it goes on sale ($200-250), shuck it, and put the internal WD Ultrastar drive in your NAS. You get an enterprise-grade CMR drive for 40-50% less than buying the internal drive separately. Just be aware of the 3.3V SATA pin issue (easy fix, covered below).

What Is Shucking?

Shucking is removing the hard drive from an external USB enclosure to use it as an internal drive in a NAS or server. Manufacturers sell the same drives in external enclosures at significantly lower prices than the bare internal versions — especially during sales.

Drive	Internal Price	External (Shuckable)	Savings
WD Ultrastar HC550 18TB	~$350-400	~$200-250 (WD Elements 18TB on sale)	37-50%
WD Ultrastar HC560 20TB	~$400-450	~$280-320 (WD easystore 20TB on sale)	25-35%
Seagate Exos X18 18TB	~$300-350	~$220-270 (Seagate Expansion 18TB on sale)	20-30%

The internal drives are identical. Same model, same firmware, same warranty — just cheaper because external drives are priced for consumers, while internal enterprise drives are priced for data centers.

Best Drives to Shuck

WD Elements / easystore — Best Value

Capacity	Drive Inside	Type	RPM	Cache	Price Range (on sale)
12TB	WD Red Plus or Ultrastar HC520	CMR	7200	256MB	~$150-170
14TB	WD Ultrastar HC530	CMR	7200	512MB	~$170-200
16TB	WD Ultrastar HC550	CMR	7200	512MB	~$190-230
18TB	WD Ultrastar HC550	CMR	7200	512MB	~$200-250
20TB	WD Ultrastar HC560	CMR	7200	512MB	~$280-320
22TB	WD Ultrastar HC570	CMR	7200	512MB	~$320-380

Why WD is the best for shucking:

All WD Elements/easystore drives 8TB+ contain CMR (Conventional Magnetic Recording) drives — no SMR
Ultrastar drives are enterprise-grade with 2.5 million hour MTBF
5-year warranty on the bare drives
Consistent quality — the “shucking lottery” is minimal with WD

When to buy: Black Friday, Amazon Prime Day, and Best Buy sales regularly drop 18TB easystore drives to $200 or below. Set price alerts on CamelCamelCamel or Slickdeals.

Seagate Expansion — Alternative

Capacity	Drive Inside	Type	Notes
12TB	Exos X16 or Barracuda Compute	CMR or SMR	Lottery — may get SMR
14TB	Exos X16	CMR	Usually safe
16TB	Exos X18	CMR	Usually safe
18TB	Exos X18	CMR	Safe
20TB	Exos X20	CMR	Safe

The Seagate problem: Lower-capacity Seagate externals (8-12TB) sometimes contain SMR (Shingled Magnetic Recording) drives, which have terrible write performance for NAS use. You won’t know until you shuck it. At 14TB+ the drives are consistently CMR, but WD is safer across the board.

How to Shuck a Drive

Tools Needed

Old credit card, guitar pick, or plastic pry tool
Small Phillips screwdriver (some models)

WD Elements / easystore Process

Remove rubber feet — peel off the rubber pads on the bottom. Some models have screws underneath.
Pry the case open — insert a credit card or plastic pry tool into the seam on the long side of the enclosure. Slide it along to release the plastic clips. Work slowly — the clips are fragile but you don’t need to preserve them.
Slide out the drive — the internal drive sits in a metal tray or rubber isolation mount. Slide it out.
Remove the drive from the mount — usually 4 screws or rubber grommets holding the drive to the internal frame.
Disconnect the USB-SATA bridge board — it plugs into the SATA data and power connectors on the drive. Gently pull it off.

The whole process takes 5-10 minutes per drive. No special skills required.

What Not to Do

Don’t use a metal tool — you’ll scratch the drive or damage the PCB
Don’t force it — if a clip won’t release, try a different angle
Don’t touch the drive’s PCB — ESD (static) can damage electronics. Ground yourself first.

The 3.3V SATA Pin Issue

This is the most common gotcha with shucked drives. Some NAS systems and SATA backplanes send 3.3V on SATA power pin 3, which triggers the drive’s power disable feature. The drive spins up briefly and then immediately spins down, appearing dead.

Which Drives Are Affected

All WD Ultrastar and HGST helium drives (most shucked drives) support the SATA 3.3 power disable feature. Whether it’s a problem depends on your power supply/backplane, not the drive.

Not affected:

Most consumer NAS units (Synology, QNAP) — they don’t send 3.3V on pin 3
Most desktop motherboards — SATA power connectors don’t include 3.3V
Molex-to-SATA adapters (they only provide 5V and 12V)

Affected:

Some server SATA backplanes
Some enterprise disk shelves
Some PSU SATA cables (newer ATX 3.0 spec includes 3.3V)

Fixes (Pick One)

Fix 1: Kapton Tape on Pin 3 (Recommended)

Cover SATA power pin 3 (the third pin from the left when looking at the power connector with the L-shaped key on the left) with a small piece of Kapton tape. This blocks 3.3V from reaching the drive.

Cut a thin strip of Kapton tape (2mm wide)
Place it over the third pin from the left on the drive’s SATA power connector
Make sure it only covers pin 3, not adjacent pins
Plug in the drive — it should now spin up normally

Kapton tape is available on Amazon for ~$5 and you’ll have enough for hundreds of drives.

Fix 2: Molex-to-SATA Adapter

Use a Molex-to-SATA power adapter. Molex connectors only carry 5V and 12V — no 3.3V. However, cheap adapters with molded SATA connectors are a fire risk (Google “molex to sata fire”). Use adapters with crimped connectors, not molded ones.

Fix 3: Modify the SATA Cable

If you’re comfortable with electronics, cut the 3.3V wire (orange) in the SATA power cable. This is permanent and prevents using the cable with drives that need 3.3V (none in a homelab context).

How to Identify Pin 3

Looking at the SATA power connector on the drive with the L-shaped key on the left:

Pin:  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15
      3V 3V 3V GN GN GN 5V 5V 5V GN GN GN 12 12 12
                ^
                Pin 3 — cover this one with Kapton tape

Warranty Considerations

WD warranty is NOT void by shucking. WD’s warranty covers the drive itself, and the serial number on the internal drive is valid for warranty claims. You can RMA a shucked drive using the drive’s serial number — WD will process it as a bare drive.

Seagate warranty: Technically the warranty is on the external product, not the internal drive. Seagate has been inconsistent about honoring warranties on shucked drives. Keep the enclosure and receipt.

Practical advice: At these prices, most homelabbers treat shucked drives as “warranty-optional.” If a drive fails in 3 years, the savings already paid for a replacement. But keep the serial numbers recorded in case you need them.

CMR vs SMR — Why It Matters

Feature	CMR	SMR
Write performance	Consistent	Drops dramatically under sustained writes
NAS suitability	Excellent	Poor
RAID rebuild time	Normal	Extremely slow (can cause second drive failure)
ZFS compatibility	Full	Problematic (zilstat issues, slow resilver)
Use case	NAS, servers, anything	Cheap archive/backup only

Never use SMR drives in a NAS. They work fine for sequential writes (backups) but degrade badly under random writes or RAID rebuilds. All WD Elements/easystore drives 8TB+ are CMR. Seagate externals under 14TB are a gamble.

How to Check if Your Drive Is CMR or SMR

After shucking, check the model number:

WD: WUH72 prefix = Ultrastar (CMR). WD80EDAZ = Red Plus (CMR). WD80EFAX = Red (SMR).
Seagate: Check against Seagate’s CMR/SMR product list. ST18000NM prefix = Exos (CMR). ST8000DM004 = Barracuda Compute (SMR).

Run smartctl -i /dev/sdX on Linux to see the model number, serial, and firmware version.

Shucking Checklist

Buy drives on sale (set price alerts)
Shuck carefully with plastic tools
Record the serial number and model number
Check CMR vs SMR (verify model against known lists)
Test with Kapton tape on pin 3 if drive doesn’t spin up
Run a full badblocks test before putting drive into production
Monitor with SMART data (smartctl -a /dev/sdX)
Store the external enclosure (for potential warranty claims)

Pre-Burn-In Testing

Before putting a shucked drive in your NAS:

# Full surface scan — writes and reads every sector
# WARNING: This destroys all data on the drive
sudo badblocks -wsvb 4096 /dev/sdX

# Check SMART health
sudo smartctl -a /dev/sdX

# Look for:
# - Reallocated Sector Count: should be 0
# - Current Pending Sector: should be 0
# - Offline Uncorrectable: should be 0

A full badblocks test on an 18TB drive takes 48-72 hours. Worth the wait to find defective drives before they’re in a RAID array.

Cost Comparison: Shucked vs Internal vs New NAS

For a 4-drive, 72TB NAS:

Option	4x 18TB Drives	Total
Internal WD Ultrastar	4 × $370 = $1,480	$1,480
Shucked WD Elements (sale)	4 × $210 = $840	$840
Savings		$640 (43%)

That $640 savings pays for the NAS itself (a Synology DS423+ is ~$550).

FAQ

Is shucking legal?

Yes. You own the drive. Removing it from the enclosure is your right. Magnuson-Moss Warranty Act (US) prevents manufacturers from voiding warranties just because you opened a product — “warranty void if removed” stickers are unenforceable.

What do I do with the empty enclosure?

Keep it for warranty claims. Or use the USB-SATA bridge board as a cheap external dock for testing other drives. Some people sell the empty enclosures on eBay.

Should I buy 4 drives at once or spread purchases?

Spread purchases across different retailers and dates. Drives from the same batch (same manufacturing date/location) may share defects. If all 4 drives come from the same production run, they may all fail around the same time.

How long do shucked drives last?

The internal drives are identical to their enterprise counterparts. Ultrastar drives are rated for 2.5 million hours MTBF (285 years). Real-world failure rates in homelabs are typically 1-3% per year per drive, similar to any other enterprise drive.

Can I shuck an SSD external drive?

You can, but the savings are minimal. SSD externals don’t have the same pricing disparity as HDDs. Just buy an internal SSD.