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Dell Precision 3551 screw size

M2 / M2.5 · 2 to 8 mm long

The screws used on Dell Precision 3551 are M2 and M2.5 in lengths from 2 to 8 mm.

There are 21 separate fitment records for it, including keyboard (qty 22) (M2), power button (qty 2) (M2) and hinge (qty 2) (M2), plus 18 more in the table below.

21 of the 21 records are marked confirmed, drawn from 1 source (dell.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.

Dell Precision 3551 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.

ThreadLengthPitchHeadDriveWhere it goesStatus
M22 mm0.4 mmnot statednot statedKeyboard (qty 22)Confirmed
M22 mm0.4 mmnot statednot statedPower button (qty 2)Confirmed
M22.5 mm0.4 mmnot statednot statedHinge (qty 2)Confirmed
M22.7 mm0.4 mmnot statednot statedHard drive (qty 4)Confirmed
M23 mm0.4 mmnot statednot statedLED board (qty 1)Confirmed
M23 mm0.4 mmnot statednot statedBracket (qty 2)Confirmed
M23 mm0.4 mmnot statednot statedCard reader (qty 4)Confirmed
M23 mm0.4 mmnot statednot statedChassis/frame (qty 6)Confirmed
M23 mm0.4 mmnot statednot statedHeat sink (qty 6, captive)captiveConfirmed
M23 mm0.4 mmnot statednot statedPower button (qty 1)Confirmed
M23 mm0.4 mmnot statednot statedSSD (qty 2)Confirmed
M23 mm0.4 mmnot statednot statedSystem board (qty 4)Confirmed
M23 mm0.4 mmnot statednot statedTouchpad (qty 2)Confirmed
M23 mm0.4 mmnot statednot statedWireless card (qty 1)Confirmed
M25 mm0.4 mmnot statednot statedChassis/frame (qty 5)Confirmed
M25 mm0.4 mmnot statednot statedHeat sink (qty 2, captive)captiveConfirmed
M26 mm0.4 mmnot statednot statedBattery (qty 1, captive)captiveConfirmed
M2.53.5 mm0.45 mmnot statednot statedDisplay (qty 4)Confirmed
M2.54 mm0.45 mmnot statednot statedHinge (qty 6)Confirmed
M2.56.3 mm0.45 mmnot statednot statedBase cover (qty 5, captive)captiveConfirmed
M2.58 mm0.45 mmnot statednot statedBase cover (qty 3, captive)captiveConfirmed

Fitment records and sources

M22 mmconfirmed

Keyboard (qty 22)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M22 mmconfirmed

Power button (qty 2)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M22.5 mmconfirmed

Hinge (qty 2)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M22.7 mmconfirmed

Hard drive (qty 4)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

LED board (qty 1)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

Bracket (qty 2)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

Card reader (qty 4)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

Chassis/frame (qty 6)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

Heat sink (qty 6, captive)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

Power button (qty 1)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

SSD (qty 2)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

System board (qty 4)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

Touchpad (qty 2)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M23 mmconfirmed

Wireless card (qty 1)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M25 mmconfirmed

Chassis/frame (qty 5)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M25 mmconfirmed

Heat sink (qty 2, captive)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M26 mmconfirmed

Battery (qty 1, captive)

pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6

M2.53.5 mmconfirmed

Display (qty 4)

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

M2.54 mmconfirmed

Hinge (qty 6)

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

M2.56.3 mmconfirmed

Base cover (qty 5, captive)

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

M2.58 mmconfirmed

Base cover (qty 3, captive)

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

How to check the screw before you buy

  1. 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).
  2. Diameter: across the threads an M2 screw measures about 2 mm with calipers (usually a hair under). This device also uses M2.5, so measure each screw rather than assuming they match.
  3. 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.
  4. Length: measure from under the head to the tip for pan, button, wafer and cap heads; countersunk (flat) heads are measured overall.
  5. The records span 2–8 mm, which means different positions take different lengths — match each hole to its own screw.
  6. Driver: the source does not name the drive. Standard M2 heads take PH0 for Phillips and T6 for Torx, and a 1.5 mm hex key for socket heads; a bit that fits loosely will cam out and strip the head.
  7. 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

  • The standard M.2 SSD screw is M2 x 3mm, but some laptops and handhelds use non-standard lengths or head shapes.
  • Xbox Series X internal chassis screws are M3, not M2 (confirmed on iFixit) — a widespread misconception.
  • Dell/HP/Lenovo manuals often list screws only by torque or head shape, so community teardowns are needed for diameter.
  • 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 Dell Precision 3551, closest length match first.

Questions about Dell Precision 3551 screws

What size screw does Dell Precision 3551 use?
M2 × 2 mm for keyboard (qty 22); M2 × 2 mm for power button (qty 2); M2 × 2.5 mm for hinge (qty 2); M2 × 2.7 mm for hard drive (qty 4); M2 × 3 mm for LED board (qty 1); M2 × 3 mm for bracket (qty 2); M2 × 3 mm for card reader (qty 4); M2 × 3 mm for chassis/frame (qty 6); M2 × 3 mm for heat sink (qty 6, captive); M2 × 3 mm for power button (qty 1); M2 × 3 mm for SSD (qty 2); M2 × 3 mm for system board (qty 4); M2 × 3 mm for touchpad (qty 2); M2 × 3 mm for wireless card (qty 1); M2 × 5 mm for chassis/frame (qty 5); M2 × 5 mm for heat sink (qty 2, captive); M2 × 6 mm for battery (qty 1, captive); M2.5 × 3.5 mm for display (qty 4); M2.5 × 4 mm for hinge (qty 6); M2.5 × 6.3 mm for base cover (qty.
How long are the screws in Dell Precision 3551?
The records range from 2 to 8 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 Dell Precision 3551?
The sources do not name the drive. For M2, Phillips heads normally take PH0 and Torx heads T6; socket heads take 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 Dell Precision 3551?
TechSpareWarehouse (our own store) lists M2 x 2mm, M2 x 2.5mm and M2 x 3mm, which match lengths in the records above.