What size screw does FPV flight-controller / ESC stacks use?

M1.4 × 4–8 mm for stack mounting bolts on 1S and 2S micro builds; M3 × 6–35 mm for the 30.5x30.5mm and 20x20mm stack patterns are M3.

How long are the screws in FPV flight-controller / ESC stacks?

The records range from 4 to 35 mm depending on the position, so match each screw to its own hole.

What is the thread pitch of an M1.4 screw?

0.3 mm (coarse), which is the standard pitch for M1.4 machine screws. The tap drill is 1.1 mm and the normal clearance hole is 1.6 mm.

What screwdriver do I need for FPV flight-controller / ESC stacks?

The sources do not name the drive. For M1.4, Phillips heads normally take PH000 / PH00 and Torx heads T2–T3; socket heads take a 1.3 mm hex key.

Can I use an imperial screw instead of M1.4?

No. Imperial look-alike: #0-80 UNF (1.52 mm) — close in diameter, different pitch, do not mix. Use a true M1.4 screw so it does not cross-thread or strip the hole.

Where can I buy replacement screws for FPV flight-controller / ESC stacks?

TechSpareWarehouse (our own store) lists M3 x 6mm, M3 x 8mm and M3 x 10mm, which match lengths in the records above.

FPV flight-controller / ESC stacks screw size

M1.4 / M3 · 4 to 35 mm long

Our records put FPV flight-controller / ESC stacks on M1.4 and M3 screws in lengths from 4 to 35 mm.

There are 2 separate fitment records for it, including stack mounting bolts on 1S and 2S micro builds (M1.4) and the 30.5x30.5mm and 20x20mm stack patterns are M3 (M3).

2 of the 2 records are marked confirmed, drawn from 2 sources (betafpv.com and en.wikipedia.org).

An M1.4 screw is 1.4 mm in diameter with a 0.3 mm pitch, tapped with a 1.1 mm drill; imperial look-alike: #0-80 UNF (1.52 mm) — close in diameter, different pitch, do not mix.

FPV flight-controller / ESC stacks 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
M1.4	4–8 mm	0.3 mm	not stated	not stated	stack mounting bolts on 1S and 2S micro builds	Confirmed
M3	6–35 mm	0.5 mm	not stated	not stated	the 30.5x30.5mm and 20x20mm stack patterns are M3thread-locking patch	Confirmed

Fitment records and sources

M1.44-8mmconfirmed

stack mounting bolts on 1S and 2S micro builds

pitch 0.3 mm · tap 1.1 mm · clearance 1.6 mm · PH000 / PH00 / Torx T2–T3

Source

M36-10mm direct, 25-35mm nylon standoffsconfirmed

the 30.5x30.5mm and 20x20mm stack patterns are M3

pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10

Source

How to check the screw before you buy

Frame and motor screws must not reach the motor windings; check the length against the motor's mounting depth.
Diameter: across the threads an M1.4 screw measures about 1.4 mm with calipers (usually a hair under). This device also uses M3, so measure each screw rather than assuming they match.
Pitch: 0.3 mm from one thread crest to the next (33.33 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 4–35 mm, which means different positions take different lengths — match each hole to its own screw.
Driver: the source does not name the drive. Standard M1.4 heads take PH000 / PH00 for Phillips and T2–T3 for Torx, and a 1.3 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 M1.4 is about 8-12 N·cm into metal threads and 4-7 N·cm into plastic bosses; snug it up and stop.

Common mix-ups with M1.4 / M3

M1.4 is THE Samsung Galaxy internal screw across S, A, M and Note lines — but lengths run 2.3mm to 4mm+ and are not interchangeable between models.
Museum/AV projector mounting kits typically bundle four to six thread sizes (M3–M6) in one bag to fit varied projector OEM patterns — always match the specific length/thread pair actually used for a given projector model rather than assuming all sizes apply universally.
M3 is the most common FPV screw, but length must match arm and stack thickness — too long can short motor windings or crack frame plates.

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 FPV flight-controller / ESC stacks, closest length match first.

E-flite Gee Bee R-2 1.0m wing securing screws also M3 × 25 mm
GetFPV anti-vibration FC standoff 7mm also M3 × 7 mm
FPV carbon frame arms and standoffs also M3 × 6–25 mm
Futaba standard servo horn screw also M3 × 8 mm
iFlight XING R5 2207 motor also M3 × 6–8 mm
Tamiya TG10-Mk.2 chassis (RC touring/on-road) also M3 × 6 mm
DJI Phantom 2 landing gear/support stand mounting screw also M3 × 6.5 mm
HP LaserJet family common hardware also M3 × 6–8 mm

Questions about FPV flight-controller / ESC stacks screws

What size screw does FPV flight-controller / ESC stacks use?: M1.4 × 4–8 mm for stack mounting bolts on 1S and 2S micro builds; M3 × 6–35 mm for the 30.5x30.5mm and 20x20mm stack patterns are M3.
How long are the screws in FPV flight-controller / ESC stacks?: The records range from 4 to 35 mm depending on the position, so match each screw to its own hole.
What is the thread pitch of an M1.4 screw?: 0.3 mm (coarse), which is the standard pitch for M1.4 machine screws. The tap drill is 1.1 mm and the normal clearance hole is 1.6 mm.
What screwdriver do I need for FPV flight-controller / ESC stacks?: The sources do not name the drive. For M1.4, Phillips heads normally take PH000 / PH00 and Torx heads T2–T3; socket heads take a 1.3 mm hex key.
Can I use an imperial screw instead of M1.4?: No. Imperial look-alike: #0-80 UNF (1.52 mm) — close in diameter, different pitch, do not mix. Use a true M1.4 screw so it does not cross-thread or strip the hole.
Where can I buy replacement screws for FPV flight-controller / ESC stacks?: TechSpareWarehouse (our own store) lists M3 x 6mm, M3 x 8mm and M3 x 10mm, which match lengths in the records above.

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