2.5in SATA SSD / HDD screw size
M3 · 3 to 4 mm long
If you are replacing a screw on 2.5in SATA SSD / HDD, the thread is M3 in lengths from 3 to 4 mm.
It is listed for the SFF-8201 standard: four M3 side holes, plus two optional bottom holes on 7mm drives.
This entry is marked confirmed and comes from members.snia.org.
For reference, M3 is 3 mm across the threads at 0.5 mm pitch. The imperial size people confuse it with: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.
2.5in SATA SSD / HDD screw specifications
One row per fitment record. Head, drive are shown only where the source states them; pitch is the ISO coarse pitch for the thread.
| Thread | Length | Pitch | Head | Drive | Where it goes | Status |
|---|---|---|---|---|---|---|
| M3 | 3–4 mm | 0.5 mm | not stated | not stated | the SFF-8201 standard: four M3 side holes, plus two optional bottom holes on 7mm drives | Confirmed |
Fitment records and sources
the SFF-8201 standard: four M3 side holes, plus two optional bottom holes on 7mm drives
pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10
How to check the screw before you buy
- Take one original screw out first and measure it before ordering; the record above tells you the thread, the original screw tells you the exact length and head.
- Diameter: across the threads an M3 screw measures about 3 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 0.5 mm from one thread crest to the next (20 crests per centimetre). A thread pitch gauge or the pitch-gauge tool settles it in seconds.
- Length: measure from under the head to the tip for pan, button, wafer and cap heads; countersunk (flat) heads are measured overall.
- The records span 3–4 mm, which means different positions take different lengths — match each hole to its own screw.
- Driver: the source does not name the drive. Standard M3 heads take PH1 for Phillips and T10 for Torx, and a 2.5 mm hex key for socket heads; a bit that fits loosely will cam out and strip the head.
- Tightening: no device-specific torque is published in these records. The site's general figure for M3 is about 80-130 N·cm into metal threads and 35-60 N·cm into plastic bosses; snug it up and stop.
Common mix-ups with M3
- 3.5in desktop and enterprise hard drives are 6-32 UNC imperial, not M3 - only the 2.5in form factor is metric.
- 3.5in drives and 5.25in bays are 6-32; 2.5in drives and motherboard standoffs are M3. Keep the two bins apart.
Buy these screws at TechSpare Warehouse
In stock and shipped from South Carolina. Our black screws are Phillips wafer head (low profile); match the head style and length to the original before you order.
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M3 x 3mm Wafer Head Screws for Synology NAS Drive Canister 2.5 SSD Bay 10-Pack
$4.99 -
M3 x 3mm SSD Mounting Screws for HP Desktop 2.5 SATA Drive Replacement 10-Pack
$4.99 -
M3 x 4mm Phillips Wafer Head Screws for 2.5 SATA SSD Mounting 10-Pack
$4.99 -
M3 x 4mm Screws for Installing SSD into Synology NAS 10-Pack
$4.99 -
M3 x 4mm Phillips Wafer Head Screws for HDD Caddy Bracket 10-Pack
$4.99 -
M3 x 4mm Phillips Wafer Head Screws for SSD Hard Drive 10-Pack Black
$4.99 -
Dell Inspiron 15 3520 Replacement Screws Sold Individually – M2 x 3mm, M2 x 5mm, M2.5 x 5mm, M3 x 3mm Phillips Wafer Head, Black
$0.10Choose size -
M3 x 3mm Laptop HDD SSD Caddy Screws 2.5" SATA Hard Drive Mount Phillips
From $11.50Choose size
More in Standards & References
The same screw also fits
Devices whose records share a thread with 2.5in SATA SSD / HDD, closest length match first.
- DIN 965 / ISO 7046 countersunk Phillips screw also M3 × 4 mm
- DIN 912 socket-head cap screw also M3 × 4 mm
- CubeSat Kit solar panel clips and chassis also M3 × 4 mm
- Lenovo ThinkPad X32 also M3 × 4 mm
- Dell Inspiron 17 7779 2-in-1 also M3 × 3 mm
- Lenovo Yoga 500-15ACL also M3 × 4 mm
- Dell Inspiron 14 3468 also M3 × 3 mm
- Lenovo ideapad 330S-15ARR also M3 × 3 mm
Questions about 2.5in SATA SSD / HDD screws
- What size screw does 2.5in SATA SSD / HDD use?
- M3 × 3–4 mm for the SFF-8201 standard: four M3 side holes, plus two optional bottom holes on 7mm drives.
- How long are the screws in 2.5in SATA SSD / HDD?
- The records range from 3 to 4 mm depending on the position, so match each screw to its own hole.
- What is the thread pitch of an M3 screw?
- 0.5 mm (coarse), which is the standard pitch for M3 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.5 mm and the normal clearance hole is 3.4 mm.
- What screwdriver do I need for 2.5in SATA SSD / HDD?
- The sources do not name the drive. For M3, Phillips heads normally take PH1 and Torx heads T10; socket heads take a 2.5 mm hex key.
- Can I use an imperial screw instead of M3?
- No. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3. Use a true M3 screw so it does not cross-thread or strip the hole.
- Where can I buy replacement screws for 2.5in SATA SSD / HDD?
- TechSpareWarehouse (our own store) lists M3 x 3mm and M3 x 4mm, which match lengths in the records above.







