What size screw does HP EliteBook / ProBook bottom case use?

M2.5 × 5 mm for torx screws for the service door and bottom cover.

How long are the screws in HP EliteBook / ProBook bottom case?

The record gives 5 mm. Measure the original from under the head (overall for a countersunk head) to confirm before ordering.

What is the thread pitch of an M2.5 screw?

0.45 mm (coarse), which is the standard pitch for M2.5 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.05 mm and the normal clearance hole is 2.9 mm.

What screwdriver do I need for HP EliteBook / ProBook bottom case?

The source lists a Torx drive. Standard M2.5 heads otherwise take PH1 (Phillips) or T8 (Torx), or a 2 mm hex key.

Can I use an imperial screw instead of M2.5?

No. Imperial look-alike: #3-48 / #4-40 (2.51 / 2.84 mm) — #4-40 is the common US stand-in and it will NOT thread in. Use a true M2.5 screw so it does not cross-thread or strip the hole.

Where can I buy replacement screws for HP EliteBook / ProBook bottom case?

TechSpareWarehouse (our own store) lists M2.5 x 5mm, which matches the length in the records above.

HP EliteBook / ProBook bottom case screw size

M2.5 · 5 mm long

If you are replacing a screw on HP EliteBook / ProBook bottom case, the thread is M2.5, 5 mm long.

It is listed for torx screws for the service door and bottom cover.

Head and drive, as the source states them: Torx drive.

This entry is marked reported and comes from support.hp.com.

For reference, M2.5 is 2.5 mm across the threads at 0.45 mm pitch. The imperial size people confuse it with: #3-48 / #4-40 (2.51 / 2.84 mm) — #4-40 is the common US stand-in and it will NOT thread in.

HP EliteBook / ProBook bottom case 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
M2.5	5 mm	0.45 mm	not stated	Torx	Torx screws for the service door and bottom cover	Reported

Fitment records and sources

M2.5~5mmreported

Torx screws for the service door and bottom cover

pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8

Source

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 M2.5 screw measures about 2.5 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
Pitch: 0.45 mm from one thread crest to the next (22.22 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 record states 5 mm. Going longer risks bottoming out or touching parts behind the hole; going shorter loses thread engagement.
Driver: the source names a Torx drive. For comparison, standard M2.5 heads take PH1 (Phillips) or T8 (Torx), or a 2 mm hex key.
Tightening: no device-specific torque is published in these records. The site's general figure for M2.5 is about 45-70 N·cm into metal threads and 20-35 N·cm into plastic bosses; snug it up and stop.

Common mix-ups with M2.5

M2.5 and M3 look the same to the naked eye — you need calipers on the shank to tell them apart.
M2.5 pitch is 0.45mm vs M3's 0.5mm and M2's 0.4mm — forcing the wrong one strips plastic bosses instantly.

Pitch gauge · Screw size finder · Torque guide

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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The same screw also fits

Devices whose records share a thread with HP EliteBook / ProBook bottom case, closest length match first.

Dell Inspiron 17 5765 also M2.5 × 5 mm
Acer Aspire 2920Z also M2.5 × 5 mm
HP mt31 Mobile Thin Client also M2.5 × 5 mm
Lenovo ideapad 330-17IKB U also M2.5 × 5 mm
Dell Vostro 16 5630 also M2.5 × 5 mm
Lenovo ideapad 320H-17IKB also M2.5 × 5 mm
Lenovo Y500 also M2.5 × 5 mm
Lenovo YOGA 730-15IKB also M2.5 × 5 mm

Questions about HP EliteBook / ProBook bottom case screws

What size screw does HP EliteBook / ProBook bottom case use?: M2.5 × 5 mm for torx screws for the service door and bottom cover.
How long are the screws in HP EliteBook / ProBook bottom case?: The record gives 5 mm. Measure the original from under the head (overall for a countersunk head) to confirm before ordering.
What is the thread pitch of an M2.5 screw?: 0.45 mm (coarse), which is the standard pitch for M2.5 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.05 mm and the normal clearance hole is 2.9 mm.
What screwdriver do I need for HP EliteBook / ProBook bottom case?: The source lists a Torx drive. Standard M2.5 heads otherwise take PH1 (Phillips) or T8 (Torx), or a 2 mm hex key.
Can I use an imperial screw instead of M2.5?: No. Imperial look-alike: #3-48 / #4-40 (2.51 / 2.84 mm) — #4-40 is the common US stand-in and it will NOT thread in. Use a true M2.5 screw so it does not cross-thread or strip the hole.
Where can I buy replacement screws for HP EliteBook / ProBook bottom case?: TechSpareWarehouse (our own store) lists M2.5 x 5mm, which matches the length in the records above.

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