What size screw does Hitec / Futaba RC servo horn use?

M2.5 × 8 mm for replacement servo horn screw, M2.5-0.45 x 8mm.

How long are the screws in Hitec / Futaba RC servo horn?

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 M2.5 screw?

0.45 mm (coarse), which is the standard pitch for M2.5 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.05 mm and the normal clearance hole is 2.9 mm.

What screwdriver do I need for Hitec / Futaba RC servo horn?

The sources do not name the drive. For M2.5, Phillips heads normally take PH1 and Torx heads T8; socket heads take a 2 mm hex key.

Can I use an imperial screw instead of M2.5?

No. Imperial look-alike: #3-48 / #4-40 (2.51 / 2.84 mm) — #4-40 is the common US stand-in and it will NOT thread in. Use a true M2.5 screw so it does not cross-thread or strip the hole.

Where can I buy replacement screws for Hitec / Futaba RC servo horn?

TechSpareWarehouse (our own store) lists M2.5 x 8mm, which matches the length in the records above.

Hitec / Futaba RC servo horn screw size

M2.5 · 8 mm long

The screws used on Hitec / Futaba RC servo horn are M2.5, 8 mm long.

It is listed for replacement servo horn screw, M2.5-0.45 x 8mm.

This entry is marked confirmed and comes from andymark.com.

For reference, M2.5 is 2.5 mm across the threads at 0.45 mm pitch. The imperial size people confuse it with: #3-48 / #4-40 (2.51 / 2.84 mm) — #4-40 is the common US stand-in and it will NOT thread in.

Hitec / Futaba RC servo horn 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
M2.5	8 mm	0.45 mm	not stated	not stated	Replacement servo horn screw, M2.5-0.45 x 8mm	Confirmed

Fitment records and sources

M2.58mmconfirmed

Replacement servo horn screw, M2.5-0.45 x 8mm

pitch 0.45 mm · tap 2.05 mm · clearance 2.9 mm · PH1 / Torx T8

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 M2.5 screw measures about 2.5 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
Pitch: 0.45 mm from one thread crest to the next (22.22 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 M2.5 heads take PH1 for Phillips and T8 for Torx, and a 2 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 M2.5 is about 45-70 N·cm into metal threads and 20-35 N·cm into plastic bosses; snug it up and stop.

Common mix-ups with M2.5

M2.5 and M3 look the same to the naked eye — you need calipers on the shank to tell them apart.
M2.5 pitch is 0.45mm vs M3's 0.5mm and M2's 0.4mm — forcing the wrong one strips plastic bosses 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 Hitec / Futaba RC servo horn, closest length match first.

Axial Racing crawler/buggy kits also M2.5 × 8 mm
Drone remote controller internals also M2.5 × 8 mm
Model aircraft control horns also M2.5 × 8 mm
Raspberry Pi (Model B+ through Pi 4/Pi 5 form factor boards) also M2.5 × 8 mm
Axial SCX10 III RC crawler, countersunk and cap screws also M2.5 × 8 mm
Antique wall clock pendulum brackets also M2.5 × 8 mm
PowerVision PowerRay underwater drone also M2.5 × 8 mm
Hitec / Futaba servo horn retaining screw also M2.5 × 8 mm

Questions about Hitec / Futaba RC servo horn screws

What size screw does Hitec / Futaba RC servo horn use?: M2.5 × 8 mm for replacement servo horn screw, M2.5-0.45 x 8mm.
How long are the screws in Hitec / Futaba RC servo horn?: 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 M2.5 screw?: 0.45 mm (coarse), which is the standard pitch for M2.5 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.05 mm and the normal clearance hole is 2.9 mm.
What screwdriver do I need for Hitec / Futaba RC servo horn?: The sources do not name the drive. For M2.5, Phillips heads normally take PH1 and Torx heads T8; socket heads take a 2 mm hex key.
Can I use an imperial screw instead of M2.5?: No. Imperial look-alike: #3-48 / #4-40 (2.51 / 2.84 mm) — #4-40 is the common US stand-in and it will NOT thread in. Use a true M2.5 screw so it does not cross-thread or strip the hole.
Where can I buy replacement screws for Hitec / Futaba RC servo horn?: TechSpareWarehouse (our own store) lists M2.5 x 8mm, which matches the length in the records above.

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