Replacement for ST-251-1: Drop-In Alternatives We Stock
Looking for a replacement for the ST-251-1 (ST-251-1 - Seagate 43MB 3600RPM MFM 5.25-inch Hard Drive)? Pro Disk Network ships Seagate drop-in replacements and equivalent modern parts from US inventory. Every alternate below is in-stock today with same-day shipping for orders placed before 2pm ET. If your unit is still under warranty, contact our engineering team — we offer cross-shipping for B2B customers on Net 30 terms.
About the ST-251-1
| SKU | ST-251-1 |
|---|---|
| Product | ST-251-1 - Seagate 43MB 3600RPM MFM 5.25-inch Hard Drive |
| Current price | $480.21 |
| Stock status | In Stock |
| Detail page | View ST-251-1 › |
Drop-in replacements for ST-251-1
Each part below is currently in our US warehouse, ships same-day for orders before 2pm ET, and includes our 90-day warranty. SKUs link to the full product page with photos, datasheets and B2B quote form.
ST-4096 - Seagate 80MB 5.25-inch Modified Frequency Modulation MFM Hard Drive
SKU: ST-4096
Price: $565.32
9SU246-251 - Seagate Constellation 7200 500GB 7200RPM SAS 6Gb/s 16MB Cache 2.5-inch Hard Drive
SKU: 9SU246-251
Price: $113.68
9LD066-251 - Seagate Savvio 15K.2 147GB 15000RPM SAS 6Gb/s 16MB Cache 2.5-inch Hard Drive
SKU: 9LD066-251
Price: $136.84
9XS066-251 - Seagate Savvio 10K.5 900GB 10000RPM SAS 6Gb/s 64MB Cache 2.5-inch Hard Drive
SKU: 9XS066-251
Price: $143.39
9XU268-251 - Seagate 1TB 7200RPM SAS 6Gb/s SFF 2.5-inch Hard Drive with Tray
SKU: 9XU268-251
Price: $259.50
9PV066-251 - Seagate Cheetah 15K.7 300GB 15000RPM SAS 6Gb/s 16MB Cache (SED) LFF 3.5-inch Hard Drive
SKU: 9PV066-251
Price: $271.04
9XM066-251 - Seagate 300GB 15000RPM SAS 6Gb/s Self-Encrypting 2.5-inch Hard Drive
SKU: 9XM066-251
Price: $291.79
How we pick replacements
Every recommendation above was selected using these criteria:
- Drop-in compatibility — same form factor (2.5"/3.5", PCIe slot, SFP port, etc.), so it fits the original chassis without modification
- Equivalent or better performance — matched on RPM/IOPS/speed/throughput, never downgraded
- Same-brand-preferred — we list the OEM-equivalent first when available, then trusted aftermarket
- Warranty coverage — 90-day Pro Disk warranty on every part, with 1-year option for B2B
- In stock today — never recommend a part that is on backorder
Need help confirming compatibility?
Our engineers validate every replacement against your specific server, switch, or chassis model before shipment. Email sales@prodisknetwork.com with your platform model (e.g., Dell PowerEdge R740, HP DL380 Gen10, Cisco Catalyst 9300) and we will confirm the exact part number that drops into your hardware.