HP 540 screw size
M2 / M2.5 / M3 · 2 to 12 mm long
Our records put HP 540 on M2, M2.5 and M3 screws in lengths from 2 to 12 mm.
There are 23 separate fitment records for it, including palm rest (qty 3, broadhead, Torx) (M2), card reader (qty 2, Phillips) (M2) and hinge (qty 4, Phillips) (M2), plus 20 more in the table below.
Head and drive, as the sources state them: Torx, Phillips and Torx T8 drives.
23 of the 23 records are marked confirmed, drawn from 1 source (tim.id.au).
For reference, M2 is 2 mm across the threads at 0.4 mm pitch. The imperial size people confuse it with: #2-56 UNC (2.18 mm) is close but not interchangeable.
HP 540 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 | Torx | Palm rest (qty 3, broadhead, Torx) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | Phillips | Card reader (qty 2, Phillips) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | Phillips | Hinge (qty 4, Phillips) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | Phillips | Optical drive (qty 2, Phillips) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | Phillips | Touchpad (qty 2, Phillips) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | Phillips | Wireless card (qty 2, Phillips) | Confirmed |
| M2 | 5 mm | 0.4 mm | not stated | Phillips | Hard drive (qty 2, captive, Phillips)captive | Confirmed |
| M2 | 5 mm | 0.4 mm | not stated | Phillips | Memory (qty 99, captive, Phillips)captive | Confirmed |
| M2 | 5 mm | 0.4 mm | not stated | Phillips | Wireless card (captive, Phillips)captive | Confirmed |
| M2 | 6 mm | 0.4 mm | not stated | Torx T8 | System board (qty 2, Torx T8) | Confirmed |
| M2 | 8 mm | 0.4 mm | not stated | Phillips | Card reader (qty 2, Phillips) | Confirmed |
| M2.5 | 10 mm | 0.45 mm | not stated | Phillips | Heat sink (qty 6, Phillips) | Confirmed |
| M2.5 | 12 mm | 0.45 mm | not stated | Phillips | Hard drive (captive, Phillips)captive | Confirmed |
| M2.5 | 3 mm | 0.45 mm | not stated | Torx T8 | Keyboard (qty 2, broadhead, Torx T8) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | Torx T8 | Speaker (qty 2, Torx T8) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | Torx T8 | System board (qty 2, Torx T8) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | Phillips | Unspecified (qty 2, Phillips) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | Phillips | Wireless card (qty 2, Phillips) | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Torx T8 | Display (qty 2, Torx T8) | Confirmed |
| M2.5 | 6 mm | 0.45 mm | not stated | Torx T8 | Display bezel (qty 8, Torx T8) | Confirmed |
| M2.5 | 7 mm | 0.45 mm | not stated | Torx T8 | Display (qty 2, Torx T8) | Confirmed |
| M2.5 | 7 mm | 0.45 mm | not stated | Phillips | Fan (qty 2, Phillips) | Confirmed |
| M3 | 4 mm | 0.5 mm | not stated | Phillips | Hard drive (qty 2, Phillips) | Confirmed |
Fitment records and sources
Palm rest (qty 3, broadhead, Torx)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Card reader (qty 2, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Hinge (qty 4, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Optical drive (qty 2, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Touchpad (qty 2, Phillips)
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
Hard drive (qty 2, captive, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Memory (qty 99, captive, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Wireless card (captive, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
System board (qty 2, Torx T8)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Card reader (qty 2, Phillips)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Heat sink (qty 6, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Hard drive (captive, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Keyboard (qty 2, broadhead, Torx T8)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Speaker (qty 2, Torx T8)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
System board (qty 2, Torx T8)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Unspecified (qty 2, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Wireless card (qty 2, Phillips)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Display (qty 2, Torx T8)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Display bezel (qty 8, Torx T8)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Display (qty 2, Torx T8)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Fan (qty 2, Phillips)
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
- A screw that is even 1 mm too long in a laptop base can push into the keyboard, battery or a board trace, so match the length position by position.
- 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 2–12 mm, which means different positions take different lengths — match each hole to its own screw.
- Driver: the source names a Torx 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
- The standard M.2 SSD screw is M2 x 3mm, but some laptops and handhelds use non-standard lengths or head shapes.
- M2.5 pitch is 0.45mm vs M3's 0.5mm and M2's 0.4mm — forcing the wrong one strips plastic bosses instantly.
- Thorlabs' 16mm cage system standard plates use dual 4-40 (UNC) and M3 taps on the same plate (e.g., SP01), so metric and imperial fasteners are both valid depending on the region/kit purchased.
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 540, closest length match first.
- Lenovo ThinkPad W530 also M2 × 4 mm
- Dell Latitude D505 also M2 × 4 mm
- HP x2 210 G2 Detachable PC - MSG") also M2 × 2 mm
- HP ProBook 440 14 inch G9 also M2 × 2 mm
- Dell Inspiron 15 7590 also M2 × 4 mm
- Lenovo V14 Gen 4 i also M2 × 2 mm
- HP EliteBook 640 14 inch G10 also M2 × 2 mm
- Dell Inspiron 14 5485 2-in-1 also M2 × 2 mm
Questions about HP 540 screws
- What size screw does HP 540 use?
- M2 × 2 mm for palm rest (qty 3, broadhead, Torx); M2 × 4 mm for card reader (qty 2, Phillips); M2 × 4 mm for hinge (qty 4, Phillips); M2 × 4 mm for optical drive (qty 2, Phillips); M2 × 4 mm for touchpad (qty 2, Phillips); M2 × 4 mm for wireless card (qty 2, Phillips); M2 × 5 mm for hard drive (qty 2, captive, Phillips); M2 × 5 mm for memory (qty 99, captive, Phillips); M2 × 5 mm for wireless card (captive, Phillips); M2 × 6 mm for system board (qty 2, Torx T8); M2 × 8 mm for card reader (qty 2, Phillips); M2.5 × 10 mm for heat sink (qty 6, Phillips); M2.5 × 12 mm for hard drive (captive, Phillips); M2.5 × 3 mm for keyboard (qty 2, broadhead, Torx T8); M2.5 × 4 mm for speaker (qty 2, Torx T8.
- How long are the screws in HP 540?
- The records range from 2 to 12 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 540?
- The source lists a Torx, Phillips and Torx T8 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 540?
- TechSpareWarehouse (our own store) lists M2 x 2mm, M2 x 4mm and M2 x 5mm, which match lengths in the records above.