Dell Inspiron 17 3785 screw size
M2 / M2.5 / M3 · 2 to 7 mm long
The screws used on Dell Inspiron 17 3785 are M2, M2.5 and M3 in lengths from 2 to 7 mm.
There are 22 separate fitment records for it, including base cover (qty 2) (M2), DC-in (qty 1) (M2) and display (qty 4) (M2), plus 19 more in the table below.
22 of the 22 records are marked confirmed, drawn from 1 source (dl.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 Inspiron 17 3785 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 | not stated | Base cover (qty 2) | Confirmed |
| M2 | 2 mm | 0.4 mm | not stated | not stated | DC-in (qty 1) | Confirmed |
| M2 | 2 mm | 0.4 mm | not stated | not stated | Display (qty 4) | Confirmed |
| M2 | 2 mm | 0.4 mm | not stated | not stated | Hinge (qty 2) | Confirmed |
| M2 | 2 mm | 0.4 mm | not stated | not stated | Optical drive (qty 2, broadhead) | Confirmed |
| M2 | 2 mm | 0.4 mm | not stated | not stated | Power button (qty 1) | Confirmed |
| M2 | 2 mm | 0.4 mm | not stated | not stated | Touchpad (qty 4) | Confirmed |
| M2 | 2.2 mm | 0.4 mm | not stated | not stated | SSD (qty 1) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | Battery (qty 4) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | Hard drive (qty 4) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | Heat sink (qty 3) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | Optical drive (qty 2) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | Power button (qty 1) | Confirmed |
| M2 | 3 mm | 0.4 mm | not stated | not stated | Wireless card (qty 1) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | not stated | I/O board (qty 1) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | not stated | Base cover (qty 1) | Confirmed |
| M2 | 4 mm | 0.4 mm | not stated | not stated | System board (qty 1) | Confirmed |
| M2.5 | 4 mm | 0.45 mm | not stated | not stated | Hinge (qty 8) | Confirmed |
| M2.5 | 5 mm | 0.45 mm | not stated | not stated | Fan (qty 3) | Confirmed |
| M2.5 | 5 mm | 0.45 mm | not stated | not stated | Hinge (qty 5) | Confirmed |
| M2.5 | 7 mm | 0.45 mm | not stated | not stated | Base cover (qty 7) | Confirmed |
| M3 | 3 mm | 0.5 mm | not stated | not stated | Hard drive (qty 4) | Confirmed |
Fitment records and sources
Base cover (qty 2)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
DC-in (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Display (qty 4)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Hinge (qty 2)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Optical drive (qty 2, broadhead)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Power button (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Touchpad (qty 4)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
SSD (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Battery (qty 4)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Hard drive (qty 4)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Heat sink (qty 3)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Optical drive (qty 2)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Power button (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Wireless card (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
I/O board (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Base cover (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
System board (qty 1)
pitch 0.4 mm · tap 1.6 mm · clearance 2.4 mm · PH0 / Torx T6
Hinge (qty 8)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Fan (qty 3)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Hinge (qty 5)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Base cover (qty 7)
pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8
Hard drive (qty 4)
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 2–7 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 / 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).
- Dell/HP/Lenovo manuals often list screws only by torque or head shape, so community teardowns are needed for diameter.
- Power-tool gearcase and clamshell screws are usually thread-forming (marked "ST") even when the parts list gives an M-size — a normal machine screw of the same size may not hold in the plastic boss.
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.
-
10x M2 x 2mm Phillips Screws for HP EliteBook 840 G6 846 G6 SSD WiFi
$4.99 -
M2 x 2mm Phillips Flat Head Screw for HP EliteBook 840/846 G6 Laptop Repair - Pack of 100 Black
$7.99 -
M2 x 3mm Screws for Dell XPS 13 9340 Base Cover SSD Shield 10-Pack Black
$4.99 -
10x M2 x 3mm Phillips Screws for Lenovo ThinkPad X131e Chromebook WiFi SSD
$4.99 -
M2 x 4mm Phillips Wafer Head Machine Screws Black 50-Pack Laptop SSD Repair
$4.49 each · min. 2
-
M2 x 4mm Screws for Dell Latitude 5530 SSD Type-C Bracket 10-Pack Black
$4.99 -
ASUS ROG Strix G15 G513R Replacement Screws Sold Individually – M1.6 x 3mm, M2 x 2.5mm, M2 x 3mm, M2.5 x 6mm Phillips Wafer Head, Black
$0.10Choose size -
ASUS ROG Strix G17 G713 Replacement Screws Sold Individually – M1.6 x 3mm, M2 x 2.5mm, M2 x 3mm, M2.5 x 6mm Phillips Wafer Head, Black
$0.10Choose size
More in Laptops & PCs
The same screw also fits
Devices whose records share a thread with Dell Inspiron 17 3785, closest length match first.
- Dell G5 15 5590 also M2 × 3 mm
- Lenovo G510s Touch also M2 × 3 mm
- HP ENVY x360 15 also M2 × 2.2 mm
- HP ProBook 430 G4 also M2 × 2 mm
- HP EliteBook 848 G3 also M2 × 3 mm
- Laptop hinge brackets (cross-brand) also M2.5 × 4 mm
- Lenovo U41 also M2 × 2 mm
- HP 2101473298; all three pages checked, same PDF) also M2 × 2 mm
Questions about Dell Inspiron 17 3785 screws
- What size screw does Dell Inspiron 17 3785 use?
- M2 × 2 mm for base cover (qty 2); M2 × 2 mm for DC-in (qty 1); M2 × 2 mm for display (qty 4); M2 × 2 mm for hinge (qty 2); M2 × 2 mm for optical drive (qty 2, broadhead); M2 × 2 mm for power button (qty 1); M2 × 2 mm for touchpad (qty 4); M2 × 2.2 mm for SSD (qty 1); M2 × 3 mm for battery (qty 4); M2 × 3 mm for hard drive (qty 4); M2 × 3 mm for heat sink (qty 3); M2 × 3 mm for optical drive (qty 2); M2 × 3 mm for power button (qty 1); M2 × 3 mm for wireless card (qty 1); M2 × 4 mm for I/O board (qty 1); M2 × 4 mm for base cover (qty 1); M2 × 4 mm for system board (qty 1); M2.5 × 4 mm for hinge (qty 8); M2.5 × 5 mm for fan (qty 3); M2.5 × 5 mm for hinge (qty 5); M2.5 × 7 mm for base cover (qt.
- How long are the screws in Dell Inspiron 17 3785?
- The records range from 2 to 7 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 Inspiron 17 3785?
- 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 Inspiron 17 3785?
- TechSpareWarehouse (our own store) lists M2 x 2mm, M2 x 3mm and M2 x 4mm, which match lengths in the records above.



