Lenovo ThinkPad T420 screw size
M2 / M2.5 · 3 to 15 mm long
Lenovo ThinkPad T420 takes M2 and M2.5 metric screws in lengths from 3 to 15 mm.
There are 20 separate fitment records for it, including keyboard (qty 1, wafer, silver) (M2), wireless card (qty 1, wafer, silver) (M2) and palm rest (qty 4, wafer, black) (M2), plus 17 more in the table below.
Head and drive, as the sources state them: wafer (thin) head.
20 of the 20 records are marked confirmed, drawn from 1 source (download.lenovo.com).
An M2 screw is 2 mm in diameter with a 0.4 mm pitch, tapped with a 1.6 mm drill; imperial look-alike: #2-56 UNC (2.18 mm) is close but not interchangeable.
Lenovo ThinkPad T420 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 | 10 mm | 0.4 mm | Wafer (thin) head | not stated | Keyboard (qty 1, wafer, silver) | Confirmed |
| M2 | 10 mm | 0.4 mm | Wafer (thin) head | not stated | Wireless card (qty 1, wafer, silver) | Confirmed |
| M2 | 15 mm | 0.4 mm | Wafer (thin) head | not stated | Palm rest (qty 4, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | LED board (qty 1, flat, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Base cover (qty 1, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | Camera (qty 1, flat, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Card reader (qty 2, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Display (qty 4, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Fan (qty 1, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Palm rest (qty 1, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Speaker (qty 3, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | SSD (qty 1, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | System board (qty 1, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Unspecified (qty 2, wafer, black)black finish | Confirmed |
| M2 | 3 mm | 0.4 mm | Wafer (thin) head | not stated | Wireless card (qty 2, wafer,flat, black)black finish | Confirmed |
| M2 | 5 mm | 0.4 mm | Wafer (thin) head | not stated | Base cover (qty 8, wafer, black)black finish | Confirmed |
| M2 | 5 mm | 0.4 mm | Wafer (thin) head | not stated | Chassis/frame (qty 2, wafer, black)black finish | Confirmed |
| M2 | 8 mm | 0.4 mm | Wafer (thin) head | not stated | Base cover (qty 5, wafer, black)black finish | Confirmed |
| M2.5 | 4 mm | 0.45 mm | Wafer (thin) head | not stated | Hinge (qty 4, wafer, black)black finish | Confirmed |
| M2.5 | 6 mm | 0.45 mm | Wafer (thin) head | not stated | Display (qty 2, wafer, black)black finish | Confirmed |
Fitment records and sources
Keyboard (qty 1, wafer, silver)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Wireless card (qty 1, wafer, silver)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Palm rest (qty 4, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
LED board (qty 1, flat, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Base cover (qty 1, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Camera (qty 1, flat, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Card reader (qty 2, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Display (qty 4, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Fan (qty 1, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Palm rest (qty 1, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Speaker (qty 3, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
SSD (qty 1, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
System board (qty 1, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Unspecified (qty 2, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Wireless card (qty 2, wafer,flat, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Base cover (qty 8, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Chassis/frame (qty 2, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Base cover (qty 5, wafer, black)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Hinge (qty 4, wafer, black)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Display (qty 2, wafer, black)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
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, 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: for wafer (thin) head screws, measure from under the head to the tip (countersunk heads are the exception: they are measured overall).
- The records span 3–15 mm, which means different positions take different lengths — match each hole to its own screw.
- 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.
- 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
- 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).
- Xbox Series X internal chassis screws are M3, not M2 (confirmed on iFixit) — a widespread misconception.
- Nylon-coated M2.5 screws (ThinkPad Edge) are thread-locking; plain replacements work loose over time.
- Dell/HP/Lenovo manuals often list screws only by torque or head shape, so community teardowns are needed for diameter.
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 Lenovo ThinkPad T420, closest length match first.
- HP Compaq nx6315 also M2 × 3 mm
- Lenovo ideapad 330 also M2 × 3 mm
- HP Pavilion ze5300 also M2 × 3 mm
- Acer TravelMate 4220 also M2 × 3 mm
- Dell Inspiron 9200 also M2 × 3 mm
- Dell Inspiron 15 5590 also M2 × 3 mm
- HP OmniBook X Flip 14 inch 2-in-1 14-fm0000 (id 2102686808) also M2 × 3 mm
- Lenovo Flex 3-1130 also M2 × 3 mm
Questions about Lenovo ThinkPad T420 screws
- What size screw does Lenovo ThinkPad T420 use?
- M2 × 10 mm for keyboard (qty 1, wafer, silver); M2 × 10 mm for wireless card (qty 1, wafer, silver); M2 × 15 mm for palm rest (qty 4, wafer, black); M2 × 3 mm for LED board (qty 1, flat, black); M2 × 3 mm for base cover (qty 1, wafer, black); M2 × 3 mm for camera (qty 1, flat, black); M2 × 3 mm for card reader (qty 2, wafer, black); M2 × 3 mm for display (qty 4, wafer, black); M2 × 3 mm for fan (qty 1, wafer, black); M2 × 3 mm for palm rest (qty 1, wafer, black); M2 × 3 mm for speaker (qty 3, wafer, black); M2 × 3 mm for SSD (qty 1, wafer, black); M2 × 3 mm for system board (qty 1, wafer, black); M2 × 3 mm for unspecified (qty 2, wafer, black); M2 × 3 mm for wireless card (qty 2, wafer,flat,.
- How long are the screws in Lenovo ThinkPad T420?
- The records range from 3 to 15 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 Lenovo ThinkPad T420?
- 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 Lenovo ThinkPad T420?
- TechSpareWarehouse (our own store) lists M2 x 3mm, M2 x 5mm and M2 x 8mm, which match lengths in the records above.





