How long are the screws in FPV drone motors (5-inch class)?

The records range from 6 to 8 mm depending on the position, so match each screw to its own hole.

What is the thread pitch of an M3 screw?

0.5 mm (coarse), which is the standard pitch for M3 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.5 mm and the normal clearance hole is 3.4 mm.

What screwdriver do I need for FPV drone motors (5-inch class)?

The sources do not name the drive. For M3, Phillips heads normally take PH1 and Torx heads T10; socket heads take a 2.5 mm hex key.

Can I use an imperial screw instead of M3?

No. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3. Use a true M3 screw so it does not cross-thread or strip the hole.

Where can I buy replacement screws for FPV drone motors (5-inch class)?

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

FPV drone motors (5-inch class) screw size

M3 · 6 to 8 mm long

Our records put FPV drone motors (5-inch class) on M3 screws in lengths from 6 to 8 mm.

The record covers FPV motor mounting on 5-inch freestyle/racing quads is predominantly M3 socket-head; length must match arm thickness plus motor base depth so the screw never touches the windings (typically 6-8mm on 4mm arms).

This entry is marked likely and comes from ligpower.com.

M3 means a 3 mm nominal diameter with a 0.5 mm thread pitch. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.

FPV drone motors (5-inch class) 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
M3	6–8 mm	0.5 mm	not stated	not stated	FPV motor mounting on 5-inch freestyle/racing quads is predominantly M3 socket-head; length must match arm thickness plus motor base depth so the screw never touches the windings (typically 6-8mm on 4mm arms)	Likely

Fitment records and sources

M36-8likely

FPV motor mounting on 5-inch freestyle/racing quads is predominantly M3 socket-head; length must match arm thickness plus motor base depth so the screw never touches the windings (typically 6-8mm on 4mm arms).

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 M3 screw measures about 3 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
Pitch: 0.5 mm from one thread crest to the next (20 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 6–8 mm, which means different positions take different lengths — match each hole to its own screw.
Driver: the source does not name the drive. Standard M3 heads take PH1 for Phillips and T10 for Torx, and a 2.5 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 M3 is about 80-130 N·cm into metal threads and 35-60 N·cm into plastic bosses; snug it up and stop.

Common mix-ups with M3

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.
On FPV motors, screw length is safety-critical: one turn too long and the screw crushes the motor windings. Measure arm + base depth, and dry-fit before powering up.

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 drone motors (5-inch class), closest length match first.

RC brushless motor mounts also M3 × 8 mm
FPV flight controller stack 30.5x30.5mm also M3 × 7–8 mm
ALware Quad Flyer Spider 500 quadcopter kit also M3 × 6–8 mm
PyroDrone anti-vibration FC standoffs also M3 × 7 mm
TBS Source One V3 / HD FPV frame also M3 × 6–8 mm
REV Robotics T-slot extrusion screw (41-1907) also M3 × 8 mm
DJI Agras Agras T50/T25/T16/T20/T30 and FlyCart 30 airframe screw also M3 × 8 mm
5-inch brushless motor to arm also M3 × 6–8 mm

Questions about FPV drone motors (5-inch class) screws

What size screw does FPV drone motors (5-inch class) use?: M3 × 6–8 mm for FPV motor mounting on 5-inch freestyle/racing quads is predominantly M3 socket-head; length must match arm thickness plus motor base depth so the screw never touches the windings (typically 6-8mm on 4mm arms).
How long are the screws in FPV drone motors (5-inch class)?: The records range from 6 to 8 mm depending on the position, so match each screw to its own hole.
What is the thread pitch of an M3 screw?: 0.5 mm (coarse), which is the standard pitch for M3 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.5 mm and the normal clearance hole is 3.4 mm.
What screwdriver do I need for FPV drone motors (5-inch class)?: The sources do not name the drive. For M3, Phillips heads normally take PH1 and Torx heads T10; socket heads take a 2.5 mm hex key.
Can I use an imperial screw instead of M3?: No. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3. Use a true M3 screw so it does not cross-thread or strip the hole.
Where can I buy replacement screws for FPV drone motors (5-inch class)?: TechSpareWarehouse (our own store) lists M3 x 6mm and M3 x 8mm, which match lengths in the records above.

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