WD Ultrastar HC550 18TB
The value anchor of the 18TB class: WD's 9-disk HelioSeal platform with conventional magnetic recording — no SMR surprises in RAID rebuilds, ever. The drive that built half the 2021-2023 hyperscale fleets, now the deepest used pool in the channel. Graded pulls and new stock ship from Hong Kong.
Fully Tested & Documented · Hong Kong Warehouse Stock · Worldwide Shipping 3–7 Days · 1-Year Warranty
Hardware Gallery
The HC550 18TB, Up Close
HC550 18TB — Label Verified
Label reads 18TB DC HC550 SATA 6Gb/s, MDL WUH721818ALE6L4, P/N 0F38459, Advanced Format. Every drive we ship is photographed and SMART-logged before packing.
PCB & SATA Interface
Rear view with the SATA data+power connector pair and green PCB. Standard 3.5-inch footprint fits any LFF hot-swap tray; 512e sector format works with legacy RAID controllers.
269
MB/s sustained transfer
550
TB/year workload rating
2.5M
hours MTBF
9
disk HelioSeal platform
Key Specifications
| Component | Specification |
|---|---|
| Model | WD Ultrastar DC HC550 18TB (WUH721818ALE6L4 / 0F38459) |
| Form Factor | 3.5-inch, 9-disk HelioSeal |
| Interface | SATA 6Gb/s, 512e (SAS 12Gb/s variant: WUH721818AL5204) |
| Recording | CMR (energy-assisted PMR), 7200 rpm, 512MB cache |
| Sustained Transfer | Up to 269 MB/s |
| Workload Rating | 550 TB/year |
| Reliability | 2.5M hours MTBF, 5-year class |
| Security | Instant Secure Erase; SED options in the family |
The HC550 18TB is the capacity-per-dollar answer when 16TB is not enough but 20TB pricing stings: two more terabytes than the Exos X18 16TB at similar channel prices. Its successor, the HC560 20TB, adds OptiNAND and two more platters' worth of density — see the FAQ for the head-to-head. Browse the full enterprise storage range.
Transparent Pricing
2026 Reference Pricing by Configuration
Tracked Sep 7, 2026 — nine asking-price data points across US/HK secondary markets, Asian B2B channels, and retail. The used pool is the deepest of any model we track — 2021-2022 hyperscaler fleets are exiting service now.
Used / Refurbished
$380-$540
eBay US used $379.99; eBay HK seller $476 (93 sold); Neology AU refurbished A$829.95 (approx $540) with 100% SMART health; PriceRunner UK £406 (approx $516, 2021 OEM old stock).
Asia Channel New
$491-$692
Colipu CN B2B CNY 3,532 (approx $491, in stock); May Chu Vina VND 13.5M excl. VAT (approx $540); Price.com.hk freecomcomputer HK$5,399 (approx $692).
US / CN Retail New
$650-$834
ASA Computers $650 (market-dependent availability); ZOL online sellers CNY 5,999 (approx $834, domestic retail).
Asking prices, not transaction prices — volume deals typically close 5-15% below asking. Small sample per tier (n<5): indicative only. Sources: ebay.com, neology.com.au, pricerunner.com, content.colipu.com, maychuvina.com, shop.price.com.hk, asacomputers.com, detail.zol.com.cn. Collected Sep 7, 2026. Full dataset: Used Server Price Index.
Origin
Hong Kong Warehouse
Free port — full export documentation
Transit
3–7 Days Air Freight
Tracked, insured, worldwide
Warranty
1-Year Warranty
Diagnostic report in every box
Quality Process
What We Test Before an HC550 18TB Ships
SMART & Helium Health
Power-on hours, reallocated/pending sectors, and helium integrity read from every drive — most channel stock is ex-hyperscaler, and we quote the hours floor openly.
Full-Surface Scan
Every LBA read-verified under sustained load; drives with slow or grown defects above threshold are rejected.
Firmware & Secure Erase
Firmware checked against WD's current release; drives sanitized to NIST 800-88 with certificate available on request.
Acoustic & Vibration Check
Spindle and seek acoustics bench-checked — the 9-disk stack telegraphs bearing wear early, and we listen for it.
PN & Sector Format Verification
Label MDL (WUH721818ALE6L4) and 512e format cross-checked against firmware identity — SAS (AL5204) and 4Kn variants circulate in the same channel.
Report in the Box
Every unit ships with its per-machine diagnostic report and warranty. Full process: inspection guide.
Frequently Asked Questions
How much does a WD Ultrastar HC550 18TB cost in 2026?
Used and refurbished units run $380-$540, Asian channel new stock $491-$692, and US/CN retail $650-$834 (nine asking prices tracked Sep 7, 2026 — small samples per tier, indicative only). It is the deepest used pool we track this year, which keeps graded-pull pricing aggressive.
What is the difference between the HC550 18TB and the HC560 20TB?
The HC560 is the direct successor: 20TB from a 10-disk stack (vs 9), OptiNAND for faster metadata handling, and otherwise the same 7200rpm helium CMR formula with a 550TB/year rating. In 2026 the HC550 typically clears $50-$150 cheaper per drive in the used channel and has far more stock depth; the HC560 buys you 11% more capacity per bay and a newer firmware line. For big RAID-6 arrays where rebuild time matters, many buyers still prefer the 18TB HC550.
Is the HC550 CMR or SMR?
CMR — conventional magnetic recording, explicitly. The entire Ultrastar DC HC500 series uses CMR (energy-assisted PMR), which is why these drives behave predictably in RAID rebuilds and ZFS resilvers. No SMR variants exist in this family; that question mostly applies to desktop WD Red lines.
What condition are HKCHL HC550 drives in?
New old stock and graded used pulls are available. Every drive ships with its SMART readout (power-on hours, reallocated sectors, helium health), a full-surface scan result, NIST 800-88 sanitization on request, and a 1-year warranty. We quote the health floor before you pay.
Can you ship HC550 18TB to the US, Europe, or Asia?
Yes — worldwide shipping from our Hong Kong warehouse with full export documentation and anti-static, foam-suspended packing; express air-freight typically arrives in 3-7 days to major markets. For JBOD-scale orders we palletize and combine freight to reduce per-unit cost.
Get a Current HC550 18TB Quote
Tell us quantity and condition preference (new old stock or graded pull with health floor) — we confirm live stock and ship worldwide from Hong Kong, usually within one business day.
Request a Quote