HP 321 screw size
M2 / M2.5 / M3 · 2 to 11 mm long
The screws used on HP 321 are M2, M2.5 and M3 in lengths from 2 to 11 mm.
There are 23 separate fitment records for it, including optical drive (qty 2, Phillips) (M2), palm rest (qty 2, Torx) (M2) and wireless card (qty 2, Phillips) (M2), plus 20 more in the table below.
Head and drive, as the sources state them: Phillips and Torx drives.
23 of the 23 records are marked confirmed, drawn from 1 source (h10032.www1.hp.com).
M2 means a 2 mm nominal diameter with a 0.4 mm thread pitch. Imperial look-alike: #2-56 UNC (2.18 mm) is close but not interchangeable.
HP 321 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 |
|---|---|---|---|---|---|---|
| M2 | 2 mm | 0.4 mm | not stated | Phillips | Optical drive (qty 2, Phillips) | Confirmed |
| M2 | 2 mm | 0.4 mm | not stated | Torx | Palm rest (qty 2, Torx) | Confirmed |
| M2 | 2.5 mm | 0.4 mm | not stated | Phillips | Wireless card (qty 2, Phillips) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | Phillips | I/O board (qty 1, Phillips) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | Phillips | Base cover (qty 4, Phillips) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | Phillips | Fan (qty 1, Phillips) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | Phillips | Hinge (qty 8, Phillips) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | Phillips | Palm rest (qty 3, broadhead, Phillips) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | Phillips | System board (qty 2, flat, Phillips) | Confirmed |
| M2.5 | 11 mm | 0.45 mm | not stated | Phillips | Hard drive (qty 2, captive, Phillips)captive | Confirmed |
| M2.5 | 3 mm | 0.45 mm | not stated | Torx | Keyboard (qty 3, broadhead, black, Torx,Phillips)black finish | Confirmed |
| M2.5 | 3 mm | 0.45 mm | not stated | Torx | Palm rest (qty 3, broadhead, black, Torx)black finish | Confirmed |
| M2.5 | 3 mm | 0.45 mm | not stated | Phillips | Unspecified (qty 2, broadhead, Phillips) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | Phillips | Battery (qty 2, Phillips) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | Phillips | Display bezel (qty 2, Phillips) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | Phillips | Hard drive (qty 1, Phillips) | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Torx | Display (qty 8, Torx) | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Phillips | Hard drive (qty 2, captive, Phillips)captive | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Torx | Keyboard (qty 3, broadhead, black,silver, Torx)black finish | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Phillips | Optical drive (qty 1, Phillips) | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Torx | Palm rest (qty 9, broadhead, black, Torx)black finish | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Torx | Wireless card (qty 1, Torx) | Confirmed |
| M3 | 4 mm | 0.5 mm | not stated | Phillips | Hard drive (qty 2, Phillips) | Confirmed |
Fitment records and sources
Optical drive (qty 2, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Palm rest (qty 2, Torx)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Wireless card (qty 2, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
I/O board (qty 1, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Base cover (qty 4, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Fan (qty 1, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Hinge (qty 8, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Palm rest (qty 3, broadhead, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
System board (qty 2, flat, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Hard drive (qty 2, captive, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Keyboard (qty 3, broadhead, black, Torx,Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Palm rest (qty 3, broadhead, black, Torx)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Unspecified (qty 2, broadhead, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Battery (qty 2, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Display bezel (qty 2, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Hard drive (qty 1, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Display (qty 8, Torx)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Hard drive (qty 2, captive, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Keyboard (qty 3, broadhead, black,silver, Torx)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Optical drive (qty 1, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Palm rest (qty 9, broadhead, black, Torx)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Wireless card (qty 1, Torx)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Hard drive (qty 2, Phillips)
pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10
How to check the screw before you buy
- Laptop covers and brackets often mix two or three lengths of the same thread, so lay the screws out in the order they came out (a magnetic mat or a sheet of paper with the hole pattern drawn on it works).
- Diameter: across the threads an M2 screw measures about 2 mm with calipers (usually a hair under). This device also uses M2.5 / M3, so measure each screw rather than assuming they match.
- Pitch: 0.4 mm from one thread crest to the next (25 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 2–11 mm, which means different positions take different lengths — match each hole to its own screw.
- Driver: the source names a Phillips drive. For comparison, standard M2 heads take PH0 (Phillips) or T6 (Torx), or a 1.5 mm hex key.
- Tightening: no device-specific torque is published in these records. The site's general figure for M2 is about 25-40 N·cm into metal threads and 12-20 N·cm into plastic bosses; snug it up and stop.
Common mix-ups with M2 / M2.5 / M3
- M.2 SSD mounting screws (M2 x 3mm) are frequently mislabeled generically as 'M.2 screws' which can be confused with the M2 metric thread designation — they do coincide numerically here but are conceptually distinct (M.2 = card format, M2 = thread size).
- M2.5 and M3 look the same to the naked eye — you need calipers on the shank to tell them apart.
- 3.5in desktop and enterprise hard drives are 6-32 UNC imperial, not M3 - only the 2.5in form factor is metric.
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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More in Laptops & PCs
The same screw also fits
Devices whose records share a thread with HP 321, closest length match first.
- Lenovo ThinkPad X13s Gen 1 also M2 × 2 mm
- Lenovo ThinkPad X9-14 Gen 1 also M2 × 2 mm
- Dell Latitude 5540 also M2 × 2 mm
- HP ProBook 4311s also M2 × 2 mm
- Lenovo Legion Y530-15ICH-1060 also M2 × 3 mm
- HP 350 G2 also M2 × 2 mm
- Dell Precision 5760 also M2 × 2 mm
- HP Pavilion DX6500 also M2 × 3 mm
Questions about HP 321 screws
- What size screw does HP 321 use?
- M2 × 2 mm for optical drive (qty 2, Phillips); M2 × 2 mm for palm rest (qty 2, Torx); M2 × 2.5 mm for wireless card (qty 2, Phillips); M2 × 3 mm for I/O board (qty 1, Phillips); M2 × 3 mm for base cover (qty 4, Phillips); M2 × 3 mm for fan (qty 1, Phillips); M2 × 3 mm for hinge (qty 8, Phillips); M2 × 3 mm for palm rest (qty 3, broadhead, Phillips); M2 × 3 mm for system board (qty 2, flat, Phillips); M2.5 × 11 mm for hard drive (qty 2, captive, Phillips); M2.5 × 3 mm for keyboard (qty 3, broadhead, black, Torx,Phillips); M2.5 × 3 mm for palm rest (qty 3, broadhead, black, Torx); M2.5 × 3 mm for unspecified (qty 2, broadhead, Phillips); M2.5 × 4 mm for battery (qty 2, Phillips); M2.5 × 4 mm f.
- How long are the screws in HP 321?
- The records range from 2 to 11 mm depending on the position, so match each screw to its own hole.
- What is the thread pitch of an M2 screw?
- 0.4 mm (coarse), which is the standard pitch for M2 machine screws; a 0.25 mm fine pitch exists but is uncommon. The tap drill is 1.6 mm and the normal clearance hole is 2.4 mm.
- What screwdriver do I need for HP 321?
- The source lists a Phillips and Torx drive. Standard M2 heads otherwise take PH0 (Phillips) or T6 (Torx), or a 1.5 mm hex key.
- Can I use an imperial screw instead of M2?
- No. Imperial look-alike: #2-56 UNC (2.18 mm) is close but not interchangeable. Use a true M2 screw so it does not cross-thread or strip the hole.
- Where can I buy replacement screws for HP 321?
- TechSpareWarehouse (our own store) lists M2 x 2mm, M2 x 2.5mm and M2 x 3mm, which match lengths in the records above.