What size screw does Futaba standard servo horn screw use?

M3 × 8 mm for servo horn (arm) screw 3x8mm, common across hobby servos.

How long are the screws in Futaba standard servo horn screw?

The record gives 8 mm. Measure the original from under the head (overall for a countersunk head) to confirm before ordering.

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 Futaba standard servo horn screw?

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 Futaba standard servo horn screw?

TechSpareWarehouse (our own store) lists M3 x 8mm, which matches the length in the records above.

Futaba standard servo horn screw screw size

M3 · 8 mm long

Our records put Futaba standard servo horn screw on M3 screws, 8 mm long.

Where it is used: servo horn (arm) screw 3x8mm, common across hobby servos.

This entry is marked confirmed and comes from futabausa.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.

Futaba standard servo horn screw 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	8 mm	0.5 mm	not stated	not stated	Servo horn (arm) screw 3x8mm, common across hobby servos	Confirmed

Fitment records and sources

M38mmconfirmed

Servo horn (arm) screw 3x8mm, common across hobby servos

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 record states 8 mm. Going longer risks bottoming out or touching parts behind the hole; going shorter loses thread engagement.
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

Thor Zone Nanoq S case mixes metric M3 (various lengths: 4, 5, 6, 10, 13, 20mm) and imperial #6-32 UNC fasteners across the same build, so builders must sort hardware carefully rather than assuming an all-metric kit.
DIN-rail terminal blocks are near-universally M3 across Dinkle, TE, Omron and RND, but torque differs (0.5-0.8 Nm) — over-torquing an M3 terminal screw strips it instantly.

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 Futaba standard servo horn screw, closest length match first.

FPV carbon frame arms and standoffs also M3 × 8 mm
FPV flight-controller / ESC stacks also M3 × 8 mm
Pinball playfield insert hardware (metric) also M3 × 8 mm
Drone motors (2205-2306 class) also M3 × 8 mm
ImpulseRC Apex EVO FPV frame also M3 × 8 mm
Drone frame arms also M3 × 8 mm
iFlight XING R5 2207 motor also M3 × 8 mm
HP LaserJet family common hardware also M3 × 8 mm

Questions about Futaba standard servo horn screw screws

What size screw does Futaba standard servo horn screw use?: M3 × 8 mm for servo horn (arm) screw 3x8mm, common across hobby servos.
How long are the screws in Futaba standard servo horn screw?: The record gives 8 mm. Measure the original from under the head (overall for a countersunk head) to confirm before ordering.
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 Futaba standard servo horn screw?: 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 Futaba standard servo horn screw?: TechSpareWarehouse (our own store) lists M3 x 8mm, which matches the length in the records above.

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