How long are the screws in 5-inch brushless motor to arm?

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 5-inch brushless motor to arm?

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 5-inch brushless motor to arm?

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

5-inch brushless motor to arm screw size

M3 · 6 to 8 mm long

The screws used on 5-inch brushless motor to arm are M3 in lengths from 6 to 8 mm.

It is listed for motor base screws for 16x16mm or 19x19mm patterns, socket head.

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

An M3 screw is 3 mm in diameter with a 0.5 mm pitch, tapped with a 2.5 mm drill; imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.

5-inch brushless motor to arm 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	Motor base screws for 16x16mm or 19x19mm patterns, socket head	Reported

Fitment records and sources

M36-8mmreported

Motor base screws for 16x16mm or 19x19mm patterns, socket head

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

Source

How to check the screw before you buy

Vibration loosens small screws on drones and RC models, so builders commonly add a drop of medium (blue) threadlocker on metal-to-metal joints — never on plastic.
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

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.
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.

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 5-inch brushless motor to arm, closest length match first.

Nerf blaster thumbscrews (mid sizes) also M3 × 8 mm
1/10 scale RC cars 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
PyroDrone anti-vibration FC standoffs also M3 × 7 mm
ALware Quad Flyer Spider 500 quadcopter kit also M3 × 6–8 mm
TBS Source One V3 / HD FPV frame also M3 × 6–8 mm
FPV flight controller stack 30.5x30.5mm also M3 × 7–8 mm

Questions about 5-inch brushless motor to arm screws

What size screw does 5-inch brushless motor to arm use?: M3 × 6–8 mm for motor base screws for 16x16mm or 19x19mm patterns, socket head.
How long are the screws in 5-inch brushless motor to arm?: 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 5-inch brushless motor to arm?: 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 5-inch brushless motor to arm?: TechSpareWarehouse (our own store) lists M3 x 6mm and M3 x 8mm, which match lengths in the records above.

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